Plants, Algae, and Fungi

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PLANTS, ALGAE, AND FUNGI

PLANTS, ALGAE, AND FUNGI

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Plants, Algae,and Fungi

Contents Grain of mallow pollen, magnified 600 times,pictured on page 1. Pollen's function is tofertilize the female organs of the plant, a taskthat is achieved with the help of bees.

BackgroundPage 6

From Algaeto FernsPage 18

Seed Plants Page 34

Rare andUseful PlantsPage 58

Fungi

Page 80

There are approximately300,000 plant species inthe world, and they live in a

variety of regions, from the frozenArctic tundra to the lush tropicalrainforests. Without plants we wouldnot be able to live; they have alwaysbeen intimately linked to life onEarth. Thanks to photosynthesis,plants provide us with food,medicines, wood, resins, andoxygen, among other things.Discovering plants' processesfor converting sunlight intocarbohydrates such as sugarsand starches is almost

magical. It is marvelous to understand howan organism that cannot move learned tomaximize the energy that it receives fromthe Sun, as well as to discover themechanisms that enable it to face so manydifferent environmental challenges. Someleaves have essential adaptations, such asthick skin, thorns, or fleshy stalks, whichallow them to survive in very dryenvironments. Others, such as the tomatoplant, form certain proteins whentemperatures drop in order to protectthemselves from damage caused by freezing.

GreenRevolution

RICE CROPRice is synonymous withfood security in much ofAsia. It is also a staplefood in western Africa,the Caribbean, and thetropical regions of LatinAmerica.

You may be surprised to learn why plantsinvest so much energy and effort intoproducing flowers. In this book we willdescribe for you in detail, step by step, howfertilization takes place. Did you know thatpollination is aided by the wind and insectsand that some flowers can be pollinated onlyby a certain species of insect? You will findall this and much more in the pages of thisbook, which includes spectacular images andillustrations that give an inside view of thecore of a tree and even show the functions ofits tissues and the veins of its leaves.

What were the first plants toconquer the Earth like, and howdid they help convert bare rock

into soil? What happened next, and whichspecies evolved and spread worldwide duringthe Carboniferous Period? A completehistorical overview of plants is included inthis book, as is an explanation of the radical

differences between plants, algae, andfungi—the latter two of which are

now considered to be more closelyrelated to animals than to plants.

Although the place of plants inthe human diet is nothing new,

the search for otherbeneficial uses of plants is a

more moderndevelopment. Crops—such as rice, corn,wheat, rye, barley, oats,soy, lentils, andchickpeas—are grown

worldwide as sources ofproteins, vitamins,

minerals, and other nutrientsnecessary for our bodies to

function, and they also providepeople with an important source

of income.

Background

According to scientificevidence, the nearest relativesof plants are algae that livedon the shores of lagoons.Later, from these habitats,

which were at times dry and at timesdamp, the first land plants emerged.Most had to adapt in order to prosperin a different environment. Suchadaptation enabled them to achieve

amazing growth, as exemplified by thegiant sequoia (Sequoiadendron

giganteum), which can measure 260 feet(80 m) tall and 100 feet (30 m) incircumference at its base. Did you know

that plants grow bigger as their cellsmultiply and expand? Many can grow 0.4inch (1 cm) per day, and their growth cancreate enough pressure to open cracks inasphalt.

KINGDOMS OF THE QUIET LIFE 8-9

AQUATIC PLANTS 10-11

CONQUEST OF LAND 12-13

ANATOMY OF A TREE 14-15

FEEDING ON LIGHT 16-17

GIANT SEQUOIA Some trees of this species arefound in central California.

Representing a vast array of life-forms, the plant kingdom includes approxi-mately 300,000 species. Their most outstanding feature is the presen-ce of chloroplasts with chlorophyll, a pigment that enables them to

transform solar energy into chemical energy. They use this energy to pro-duce their food. Plants need to attach themselves to a substrate (usually the ground), from which they can extract water and nutrients. Thisattachment, however, also keeps them from moving from place to place.Algae and fungi were once included in the plant kingdom, but they are now considered to be separate from plants and to belong to the kingdoms

Protista and Fungi, respectively.

Kingdoms of the Quiet Life

Algaeare commonly considered water plants, but this is not thecase. Algae have neither roots nor stalks. Because they live inthe water (freshwater or salt water), they need no substrate.Some are microscopic, but large algae formations can befound in the ocean. Algae are classified into familiesdepending on their color. Together green algae and plantsmake up the group of organisms called the “green line,” whosemembers are characterized by having chloroplasts and bystoring grains of starch in the cytoplasm as a reserve.

PlantsThe plant kingdom (Plantae) includes organismswhose characteristics include the presence of the

pigment chlorophyll to convert solar energy intochemical energy for producing food from water andcarbon dioxide. This ability is called autotrophy. Allplants, whether large or small, play an extremelyimportant role in providing food for all other livingbeings. Plants cannot move from place to place, buttheir gametes, spores (cells that separate from a plantand can germinate), and seeds can move about,especially with the help of water and wind.

Fungibelong to a different kingdom from that ofplants. Fungi, unlike plants, do not carry outphotosynthesis, and they store energy in theform of glycogen rather than starch. Fungi areheterotrophic (they get their food from otherorganisms), and they take in food by absorption.Fungi can be either parasitic or feed on deadorganic material. Some fungi are microscopic;others are large and conspicuous. Theirbodies are composed of a mycelium, a massof filaments called hyphae. Some fungi alsohave a fruit-bearing structure.

SPIKE MOSShas scalelikeleaves, some ofwhich areclustered in theform of a spike.

FERNSare the most diversegroup of seedlessplants. Their origindates back to theDevonian Period.

PSILOPHYTAare extremely simpleplants; they lackroots and trueleaves, but they havea stalk with veins.

HORSETAILRUSHEShave roots, stems, andtrue leaves. The leavesare small and encirclethe stems.

CEREALSare monocotyledons.Their seeds have onlyone cotyledon(embryonic leaf), andtheir mature leaveshave parallel veins.

ORCHIDShave many petals; their numberof petals is always a multiple ofthree. This makes them, alongwith cereal grains,monocotyledons (monocots).

8 BACKGROUND

GymnospermaThe Greek word means “naked seed.”Gymnosperms are vascular plants withexposed seeds and no flowers. Ginkgos(Ginkgophyta) and cycads (Cycadophyta) werethe most common plant groups in ancienttimes. Today conifers (such as pines, larches,cypresses, and firs) are the most commontype. Conifers are monoicous—that is, thesame plant has both male and female sexualorgans—and their seeds are held between thescales of a structure called a cone.

CYCADSare tropical plants that looklike palm trees. Theirreproduction is similar tothat of pine trees, but theyare dioecious (each plant hasflowers of only one sex).

GINKGOSOnly one speciesis left in thisgroup, which isthe oldest genusof living trees.

GNETOPHYTAPlants with nakedseeds and avascular systemsimilar to that ofangiosperms

FERNOsmunda sp.

MOSSSphagnum sp.

RED MARINEALGA Rhodomela sp.

SeedlessFerns are the most common seedlessplants today. Many are thought tohave originated during the DevonianPeriod and reached their greatestsplendor in the Carboniferous Period.Their tissues are simpler than thoseof plants with seeds, and their greenstems have a large surface area,giving them a great capacity forphotosynthesis. Ferns need water sothat they can reproduce by means ofspores. The spores are produced inspore cases called sporangia, whichgrow on leaves called sporophylls.

Bryophytesinclude mosses and worts. Mosses have rhizoidsrather than roots. They can also absorb waterthrough their entire body surface. Bryophytes lack ameans of surviving long periods of drought. Whendry periods come, bryophytes enter a latent state.Because they have no system of veins fortransporting nutrients, they can barely grow beyond0.4 inch (1 cm) long. In order to reproduce they needto be near liquid water.

ORCHIDCattleya trianae

SITKA SPRUCEPicea sitchensis

WHITEMUSHROOM

Agaricus bisporus

WHEATTriticum sp.

HorsetailRushes

SEEDLESS

WITH VEINSWITHOUT VEINS

WITH SEEDS

PLANTS

Psilophyta

ClubMosses Ferns

Cycads

Anthophytaor

FloweringPlants

Bryophytes(Mosses)

GreenAlgae

Ginkgo

Gnetophyta Conifers

CONIFERSare the most abundant plantswith seeds today. Theirreproductive structures arecalled cones. Most conifers areevergreens.

Angiospermshave seeds, flowers, and fruit. They include morethan 250,000 species and are adapted to nearly allenvironments except for Antarctica. They reproducesexually by producing flowers that later form fruitswith seeds. Angiosperms have an efficient vascularsystem for transporting water (through the xylem)and food (through the phloem). Angiosperms makeup a division of the plant kingdom that includesplants with bright flowers; grains, such as rice andwheat; other crops, such as cotton, tobacco, andcoffee; and trees, such as oak, cherry, and chestnut.

Rooted Plants with Floating LeavesSuch plants are often found in standing or slow-moving water. They havefixed rhizomes and petiolate leaves (leaves with a stalk that connects to astem) that float on the surface of the water. Some of the plants havesubmerged leaves, some have floating leaves, and some have leaves outsidethe water, with each type having a different shape. In the case of floatingleaves the properties of the upper surface are different from those of thelower surface, which is in contact with the water.

Rooted Underwater PlantsThe entire plant is submerged. The small root systemserves only to anchor the plant since the stem can directlyabsorb water, carbon dioxide, and minerals. These plantsare often found in flowing water. The submerged stemshave no system of support—the water holds up the plant.

Amphibious or Wetland Plants These species live on the edges of ponds, rivers, and swamps.They are also found in salt marshes, which are periodicallyflooded by tides or river overflows. These plants are a transitionbetween aquatic and land plants. Their limiting factor is theavailability of oxygen, so they have well-developed aerenchyma.

Submerged or FreeSome underwater plants are free, without roots, butwith developed stalks and divided leaves. Otherfloating plants have a rosette shape and leavesmodified for floating; they have well-developed rootswith root caps but without absorbent hairs. The rootshelp the plant to stay balanced on top of the water.

Floating LeavesThe rhizomes are fixed, the leaves grow onlong stalks, and the leaf surface floats onthe water.

Upper Epidermis

LowerEpidermis Conduction

Bundle

Aquatic but ModernThe evolutionary history of plants began inwater environments. They later conquered land

by means of structures such as roots. Modern aquaticplants are not a primitive group, however. On thecontrary, they have returned to the water environmentby acquiring highly specialized organs and tissues. Forexample, some tissues have air pockets that enable theplant to float.

A Vital RoleAquatic plants play animportant role in the ecosystem

not only for crustaceans, insects, andworms but also for fish, birds, andmammals because they are animportant source of food and shelterfor these categories of animals.Aquatic plants also play a major role inconverting solar energy into theorganic materials upon which manyliving things depend.

AirChamber

Aerenchyma

Parenchyma

EpidermisAirChamber

Aerenchyma

THE NUMBER OF WELL-KNOWN SPECIESOF WATER PLANTS300

PPLANTS, ALGAE, AND FUNGI 11

Aquatic Plants

TROPICAL WATER LILYVictoria crucianaIt grows in deep, calm waters.Its leaves can measure up to 7feet (2 m) across.

PARROT FEATHERMyriophyllum aquaticumThis plant is native to temperate,subtropical, and tropical regions, and itis highly effective at oxygenating water.

KNOTWEEDPolygonum sp.This aquatic plant growsin marshy vegetation.

BLADDERWORTUtricularia vulgarisThese carnivorousplants complementtheir diet with smallaquatic creatures.

EELGRASSVallisneria sp.This oxygenating plant isfound in ponds and aquariums.

LACHENALIALachenalia viridifloraThis plant isattractive, with alarge number offlowers.

ARROWHEADSagittaria sagittifoliaIts flowers, with three whitepetals and purple stamens,form during the summer.

CATTAILSTypha sp.grow in moist soil,around lake margins,and in marshes inboth temperate andtropical climates.

YELLOW FLOATING HEARTNymphoides peltataIt produces small creasedyellow flowers all summerlong.

HORNWORTCeratophyllum sp.This plant has anabundance of fineleaves that form aconelike structureon each stem.

The roots andrhizomes underthe water arewell developed.

They produce andrelease oxygen as aresult of photosynthesis.

Submerged stems have no support system because the water holds up the plant. Their limitingfactor is oxygen availability, so the aerenchymahelps make this substance available to the plant.

The underwaterparts do nothave animpermeableouter layer, sothey can absorbminerals and gasesdirectly fromthe water.

Aquatic plantwith especiallybeautiful flowers.

10 BACKGROUND

These plants are especially adapted for living in ponds, streams, lakes, and rivers—places where otherland plants cannot grow. Although aquatic plants belong to many different families, they have similaradaptations and are therefore an example of adaptive convergence. They include submerged plants and

floating plants; plants that may or may not be rooted at the bottom; amphibious plants, which have leavesboth above and below the water's surface; and heliophilic plants, which have only their roots underwater.

SAGO PONDWEEDPotamogeton densusThis water plant canbe found in shallowdepressions of clear-flowing streams.

Aerenchymais always found in floating organisms. This tissuehas an extensive system of intercellular spacesthrough which gases are diffused.

Pneumatophoresare floating roots that are involved in airexchange. They take oxygen from thesurface, and it circulates to the rest ofthe plant through its intracellularspaces. They probably also allow carbondioxide to escape. Certain plants have aspecial adaptation that consists of airsacs that store oxygen for periods whenthe plant will be submerged or thatspeed up the plant's transpiration.

Grassestake advantage of long hours ofsummer daylight to grow andreproduce. Their stalks do not havereinforcing tissues that wouldenable them to remain erect.

GiantsTrees are distinguished by their woody trunks. As atree grows from a tender shoot, it develops a tissuethat gives it strength, enabling it to grow over 330feet (100 m) tall. Trees are found in the principalterrestrial ecosystems.

Epiphytes grow on plants or on some othersupporting surface. Their anatomyincludes secondary adaptationsthat enable them to live withoutbeing in contact with the soil.

Conquest of Land

12 BACKGROUND

The movement of plants from shallow water onto land isassociated with a series of evolutionary events. Certain changesin the genetic makeup of plants enabled them to face the new and

extreme conditions found on the Earth's surface. Although land habitatsoffered plants direct exposure to sunlight, they also presented theproblem of transpiration and the loss of water that it produces. Thisdifficulty had to be overcome before plants could spread over land.

MOSSSphagnum sp.Bryophytes arethe simplest of allland plants.

MALE FERNDryopteris filix-masThese vascularplants need liquidwater to reproduce.

SWEET VIOLETViola odorataThis plant'sspring flowershave a pleasantscent.

STEMLESSSOW THISTLESonchus acaulisThese plantslack a stem.

Vital ChangesRoots are among the most importantadaptations for plants' success in land

habitats. Root systems anchor the plant inthe substrate and serve as a pathway forwater and mineral nutrients to enter it.Besides roots, the development of a cuticle(skin membrane) to cover the entire plant'ssurface was crucial. Cells in the epidermisproduce this waterproof membrane, whichhelps the plant tolerate the heat generatedby sunlight and the wear and loss of watercaused by the wind. This protection isinterrupted by pores, which allow for gas exchange.

Green RevolutionLeaves are the main organs for photosynthesis in landplants. After plants appeared on land more than 440million years ago, the amount of photosynthesis takingplace gradually increased. This increase is believed tobe one of the reasons the concentration of carbondioxide in the atmosphere decreased. As a result, theEarth's average temperature also decreased.

SPECIES OF FUNGUS LIVE ALONGSIDE LAND-DWELLING PLANTS.

50,000

THE HEIGHT REACHED BY SOMESEQUOIA SEMPERVIREN TREES

360 Feet(110 M)

CHESTNUTSCastanea sp.

WALNUTSJuglans sp.

BEECHESFagus sp.

MAPLESAcer sp.

OAKSQuercus sp.

LINDENSTilia sp.

Oak-Tree ProductsThe bark is rich in tannin, which

is used in curing leather and as anastringent. The wood is strong andresists rotting.

Growth Rings

Anatomy of a Tree

14 BACKGROUND PLANTS, ALGAE, AND FUNGI 15

The oak tree is the undisputed king of the Western world. It isknown for its lobed leaves and the large cap of its acorn, anut found on all trees of the genus Quercus. The tree's

main trunk grows upward and branches out toward thetop. Oaks are a large group, containing many types ofdeciduous trees. Under optimal conditions oaks cangrow to a height of more than 130 feet (40 m) andlive an average of 600 years.

Rootsgrow sideways to form adeep, broad root system.

Budsare formed by protectivescales that fall off in thespring. They grow into newleaves and branches.

TrunkThe trunk is strong andgrows straight upward. Thetop of the tree widens withbranches, which may betwisted, knotted, or bent.

FlowersThe tree produceshanging maleflowers, whereasfemale flowers arehidden among theleaves.

Bark

Leavesare arranged one leaf to astem on alternating sidesof the twig. They haverounded lobes on eitherside of the main vein.

Acornshave dark stripes alongtheir length. Their capshave flat scales.

SeedsSome species have sweet-tasting seeds; others are bitter.

BeginningsIn its first year of life anoak tree's roots can grownearly 5 feet (1.5 m).

Achene: A hardseed that doesnot split open atmaturity

Remains of theCarpel (femalereproductive part)

AutumnThe cells at theend of each leafstem weaken.Summer

The leaves undertakephotosynthesis, and therest of the tree uses thesugars it produces.

WinterThe leaf falls away,and the treeremains dormant.

Spring The cycle beginsas the first leavesappear.

AutumnLow temperaturesweaken thebranches.

WinterThe leaves fall away;the tree is dormantuntil spring.

SpringNew leavesbegin to replacethe old ones.

The leaves absorbCO2 and producesugars by meansof photosynthesis.

Transpiration(the loss ofwater vapor) inthe leaves pullsthe xylem sapupward.

THE AVERAGE LIFESPAN OF AN OAK

600years

ClimateTrees grow in any place where there is sufficientwater in the soil.

Energy SourceThe chlorophyll traps energyfrom sunlight and uses it toconvert water and carbondioxide into food.

SurfaceMosses use the bark of oaktrees as a source of moisture.

SummerThe oak blossoms.It increases inheight, and its trunkgrows thicker.

Woodpeckers drillholes in the treewith their beaksas they look for

insects.

The xylemtransportswater andminerals fromthe roots to therest of the tree.

Absorption of Water and Minerals

The phloemtransportssugars from theleaves to therest of the tree.

Feeding on Light

16 BACKGROUND

Stages of the ProcessPhotosynthesis takes place in two stages. The first, calledphotosystem II, depends directly on the amount of light

received, which causes the chlorophyll to release electrons. Theresulting gaps are filled by electrons of water,which breaks down and releases oxygenand ionized hydrogen (2H+).

ATP formation is powered bythe movement of electronsinto receptor molecules in achain of oxidation andreduction reactions.

1 In photosystem I lightenergy is absorbed, sendingelectrons into otherreceptors and makingNADPH out of NADP+.

2

In photosystem I ATPis also generated fromADP because of thesurplus flow of freeelectrons.

4

The ATP and NADPHobtained are the netgain of the system, inaddition to oxygen. Twowater molecules aresplit apart in theprocess, but one isregenerated when theATP is formed.

3

CarbonTHE BUILDING BLOCK OFORGANIC MATERIALS

ThylakoidsSacs that contain chlorophyll molecules.Inside them ADP is converted into ATP as a product of the light-dependent phaseof photosynthesis. Stacked thylakoidsform a structure called a grana.

The Dark PhaseThis phase, so called because it does not directlydepend on light, takes place inside the stroma of

the chloroplast. Energy in the form of ATP and NADPH,which was produced in the light-dependent phase, isused to fix carbon dioxide as organic carbon through aprocess called the Calvin cycle. This cycle consists ofchemical reactions that produce phosphoacylglycerides,which the plant cell uses to synthesize nutrients.

CellMembrane

Cell Wall

Nucleus

Grana

Nucleole

Vacuoleprovides waterand pressureand gives thecell consistency.

Plant Cellshave three traits that differentiate themfrom animal cells: cell walls (which aremade up of 40 percent cellulose), a largevacuole containing water and tracemineral elements, and chloroplastscontaining chlorophyll. Like an animalcell, a plant cell has a nucleus.

Why Green?Leaves absorb energy from visible light, whichconsists of different colors. The leaves reflectonly the green light.

Leavesare made of severaltypes of plant tissues.Some serve as asupport, and someserve as filler material.

Algaeperform photosynthesis underwater.Together with water plants, they providemost of the atmosphere's oxygen.

OXYGENis a by-product ofphotosynthesis. It exitsthe surface of the leavesthrough their stoma(two-celled pores).

WATERPhotosynthesis requiresa constant supply ofwater, which reachesthe leaves through theplant's roots and stem.

CARBONDIOXIDEis absorbed byplant cells to formsugars by meansof photosynthesis.

Plant TissuesThe relative stiffness of plantcells is provided by cellulose, thepolysaccharide formed by theplant's cell walls. This substanceis made of thousands of glucoseunits, and it is very difficult tohydrolyze (break down in water).

O2

IS RELEASED BYPLANTS INTO THEEARTH'S ATMOSPHERE

CHLOROPHYLLis the most abundantpigment in leaves.

ChloroplastThe part of the cell whereboth phases of photosynthesistake place. It also containsenzymes.

Stromais the watery spaceinside the chloroplast.

+ ADP

CO2

ATP

H + NADP+

NADPH

CalvinCycle

P

ENDPRODUCTSenable the plantto generatecarbohydrates,fatty acids, andamino acids.

PHOTOSYSTEM II

PHOTOSYSTEM I

ProteinNADP+

Reductase

NADPH

H2O

2H+

ThylakoidMembrane

O2

2H+

Flow ofElectrons

H+

P

ADP+

ATP

An important characteristic of plants is their ability to use sunlight and thecarbon dioxide in the air to manufacture their own complex nutrients.This process, called photosynthesis, takes place in chloroplasts, cellular

components that contain the necessary enzyme machinery to transform solar energy intochemical energy. Each plant cell can have between 20 and 100 oval-shaped chloroplasts.Chloroplasts can reproduce themselves, suggesting that they were once autonomousorganisms that established a symbiosis, which produced the first plant cell.

PLANTS, ALGAE, AND FUNGI 17

STRANGE BEDFELLOWS 28-29

MOSSES 30-31

DISPERSION OF SPORES 32-33

From Algae to Ferns

Algae (including seaweed) donot belong to the plantkingdom, because they do nothave all the characteristicsand functions of plants. Algae

have neither roots nor stems. Becausethey live in water, they do not need thesestructures for absorbing water. Algaegrow on the sea floor or on the surfaceof rocks in the ocean, in rivers, and in

lakes. Their shape and color areextremely varied. The annual worldharvest of algae is estimated at morethan 1 million tons in dry weight. Asiancountries (Japan and China) produce 80

percent of the world's harvest. Algae areused in agriculture, the food industry,pharmaceuticals, preservatives, andmedicine. They are an important sourceof income for many workers.

COLORS OF LIFE 20-21

HOW ALGAE REPRODUCE 22-23

TERRESTRIAL AND MARINE ALGAE 24-25

THE ALGAE INDUSTRY 26-27

DIATOMACEOUS ALGAEThe scientific name of this type ofsingle-celled algae is Biddulphia laevis.It is usually found close to the surfaceof very shallow bodies of water.

often have flagella that enable them to move through thewater. Most have the ability to ingest solid material through

phagocytosis. Single-celled algae include some distinctive groups.Diatoms are covered with a protective shell made of silicon. Somesingle-celled algae, namely red algae, can thrive at relatively hightemperatures. Red algae is unique among eukaryote organisms inits ability to live inside thermal water vents.

Single-Celled Organisms

This group of algae includes multicelled structures.They form colonies with mobile, single-celled algae

that group together more or less regularly in a sharedmucilaginous capsule. They can also appear in threadlikeshapes, which branch off, or in bulky shapes, which aremade up of layers of cells with a particular degree ofcellular differentiation, that together are called a thallus.

Multicelled Organisms

6,000DIFFERENT SPECIEShave been classified within this groupof green algae, or chlorophytes.

PLANTS, ALGAE, AND FUNGI 2120 FROM ALGAE TO FERNS

Colors of LifeA

lgae are living things that manufacture their own food usingphotosynthesis. Their color is related to this process, and it has beenused as a way of classifying them. They are also grouped according

to the number of cells they have. There are many kinds of one-celled algae.Some algae form colonies, and others have multicellular bodies. Some types ofbrown seaweed can reach a length of more than 150 feet (45 m).

Fucus vesiculosus

Pinnularia borealisAcetabularia crenulata

Chlamydomonas

Scenedesmusquadricauda

Micrasteria staurastrum

Micrasteria rotata

Nitophyllumpunctatum

Mallomonas

Carrageen red seaweed Bangiaatropurpurea

Hypoglossumhypoglossoides

Halymenia floresia Apoglossumruscifolium

Cystoseira amantaceastricta

Dictyota dichotoma hudsonlamouroux

Ectocarpussiliculosus

Dictyota dichotoma implexa

GREAT OPPORTUNISTSSingle-celled algae live near thesurface of bodies of water. When theyfind an area with light and thenutrients necessary for development,they use asexual reproduction tomultiply and colonize the area.

Phaeophytesare the 1,500 species of brown seaweed. They inhabittemperate regions and therocky coasts of the coldestseas on Earth. Their colorcomes from the pigmentfucoxanthin, a xanthophyll that masks the green color of their chlorophyll.

1

Chlorophytesconstitute the group of green algae. Themajority of species are microscopic, single-celled organisms with flagella. Others forminto filaments, and yet others form largemulticellular bodies. The group Ulvophyceaeincludes sea lettuce, which resembles a leaf oflettuce and is edible. The group Charophyceaeincludes stoneworts, which contain calciumcarbonate deposits. The chlorophytes arelinked evolutionally with plants because theycontain the same forms of chlorophyll, andtheir cell walls contain cellulose.

2

Rhodophytesare characterized by their phycoerythrin pigments, whichgive the algae a reddish color by masking their chlorophyll'sgreen color. Most rhodophytes grow below the intertidalzone near tropical and subtropical coasts. They aredistributed throughout the principal oceans of the world and grow mainly in shaded areas in warm, calm water.

3

22 FROM ALGAE TO FERNS PLANTS, ALGAE, AND FUNGI 23

How Algae ReproduceT

he reproduction of algae can be sexual or asexual in alternating phases, depending on the speciesand on environmental conditions. Vegetative multiplication occurs through fragmentation orthrough the production of spores. In sexual reproduction the fertilization of the gametes (sexual

cells) produces a zygote that will give rise to a new alga. During asexual reproduction there is no geneticexchange, and the algae produced are clones of the original. Sexual reproduction, in contrast, producesalgae with new characteristics that may help them to better adapt to their environment.

Sporophytes generate spores in every speciesof microscopic algae. New individuals born

from these spores are called gametophytes, and theyproduce gametes, which can be male, female, orhermaphrodite. During fertilization the male gametes(antheridia) and the female ones (ovum) form a cellcalled a zygote, which develops into a new thalluswhen it grows. Gametocytes and sporophytescan vary in morphology. If they are similar,they are called isomorphic, and if they aredifferent, they are called heteromorphic.

Sexual

JOURNEYOnce they become detached,antherozoids use their flagellato move in the water.

FEMALE FUCUSThe receptacles secrete agreenish gelatin made up offemale gametes. The gametesare freed when the sac thatcontains them breaks.

APPROACHThe journey of the antherozoidscoincides with the opening ofthe female gametangia.

ANOTHER CYCLEThe youthful thallus,

when mature, producesspores.

Asexual reproduction does not involve fertilization.It can take place in either of two ways. In

fragmentation, segments of an alga become detachedfrom its body, and, since the alga does not have anyspecialized organs, the segments continue to grow as longas environmental conditions remain favorable. The otherform of asexual reproduction is by means of spores,special cells that form from a normal cell. Some algaespores have one or more filaments, or flagella, thatallow the alga to swim freely. When theappropriate environmental conditionsare found, the spores germinateinto new algae.

Asexual

Transverse cutfrom a Fucusspecies thallus

MALEFUCUSThe male fucushas receptaclesin whichantheridia form.

New ThallusAfter fertilization the zygote dividesand creates the embryo, a small cellmass that attaches to rocks, where anew thallus of Fucus species grows.The thallus looks similar to the stem ofplants, and it contains blades that looklike leaves.

FertilizationBoth fertilization and asexualreproduction are the naturalmeans of perpetuation for thisspecies. Algae form newindividuals similar to themselvesthrough reproduction. When anantherozoid penetrates theovum, it fertilizes the egg andforms a zygote.

23

AntheridiumThe male gametangia (structure that producesgametes). They produce antherozoids, whichhave two flagellae and are smaller than theovum, or female gamete. They swim until theyreach an ovum and then surround it.

1

OvumIn the reproductive stage female gametangia format the tips of the thalluses. This is where the femalesexual cells (ova) develop.

1

OPENINGThe sac that containsthe ovum opens.

ZOOSPOREA structure that canproduce a newindividual asexually

LIGHTAs depth increases, water

absorbs sunlight andproduces a loss in color.

7,000SPECIES OF GREEN ALGAEexist, and they have diverse characteristics.The majority live in the ocean, and most ofthose remaining live in freshwater.

1DepthMarine algae live where sunlightcan reach them. Sunlight iscompletely absorbed at a depthof 650 to 1,300 feet (200–400m). Green and brown algae areusually found near the shore;they also live in stagnantterrestrial bodies of water.Green, brown, and red algae canappear farther from shore indeeper waters, and red algaelive in even deeper waters. Eacharea represents a specific typeof habitat, with a characteristiccomposition of flora and fauna.

2 Concentration of SaltsThe waters that cover the Earth's surface are classified intotwo types: salt water, which forms the oceans and seas,and freshwater, or continental water. Marine water has aconcentration of dissolved salts that is generally consideredto be uniform. In contrast, the salt concentration ofcontinental water can vary from place to place, causing itto have a different effect on living organisms.

3 Water TemperatureTemperature, which varies according to latitude and marine currents, plays animportant role in determining where algae can live. The energy that the Sun'sradiation provides to the oceans varies with its angle of incidence, but currents andtides distribute this energy. Ocean temperature is also dependent on depth—as thedepth increases, the temperature decreases.


Terrestrial and Marine AlgaeA

s long as there is water, the survival of an alga is assured. Algae are found both in theoceans and in freshwater, but not all can survive in both environments. Depth,temperature, and salt concentrations of water are characteristics that

determine whether algae can live in a given area. Algae can be green, brown,or red. Of the three, red algae are found in the deepest waters. Somespecies of algae can live outside of water, but they are neverthelessfound in humid places, such as in mud or on stone walls or rocks.

FUCUS

PORPHYRA

ULVA

MACROCYSTIS

CODIUM

ULVA

MACROCYSTIS

PORPHYRA

LITTORAL ZONE

INFRALITTORAL ZONE

SUPRALITTORALZONE

MARINE WATER

EARTH

SUN

FRESHWATER

Brown, Green,and Red Algae

Green andBrown Algae

Salts %Ca2+ 1.2

Mg2+ 3.7

Na+ 30.6

K+ 1.1

Cl- 55.1

SO2- 7.7

HCO- 0.44

3

4

3

Salts %Ca2+ 17

Mg2+ 3.4

Na+ 3.0

K+ 1.8

Cl- 3.3

SO2- 8.2

HCO- 63.5

0

50

100

150

200

250

MoreIncidence

LessIncidence

LessIncidence

Red Algae

Dep

th (

in m

eter

s) (

1 m

= 3

.3 f

t)

COLLECTIONLarge algae are collectedwith cranes from a boat;small algae are collectedby hand or with rakes.

FILTERINGThe noxiousresidues areeliminated.Then the algaeare filtered andtransported toa tank.

BASINScan withstand hightemperatures. In the lastbasin the mass is cookedat 212° F (100° C).

GELLINGoccurs when thetemperature is loweredalong the length of thepipe to 77° F (25° C).

PRECAUTIONThe dried algaemust be groundimmediately toprevent it frombecoming moist.

FILTER1.5TONS PER DAYThe amount of Gelidium algaeextractd by hand in Japan.

MILLINGThe dry groundagar is milled toreduce particle size.

In China algae have been used for food, as well as for traditional medicine, forthousands of years. However, the algae industry began on a broad scale in the17th century in Japan with the production of caustic soda and potassium

hydroxide from the ashes of brown algae. A century later Western countriesbegan to exploit algae in order to extract iodine and other chemical compoundsof great economic value, such as phycocolloids (gelatin-like substances that canbe obtained from several species of algae). The most commonly usedphycocolloids are agar, carrageenan, and algin.

How Agar Is ObtainedMost algae collection is still done by hand, althoughcommonly used large species, such as the

Caribbean Sargasso, are also collected with special boatsin which processing of the algae can begin. The firststages, especially drying, are typically carried out bynatural methods, but large fire-heated drying drums areused in some countries of Europe and North America.Although the use of heated drums is more expensive, itcan result in a product of higher quality.

DRYINGprevents the algae from

rotting. Algae are firstwashed with seawater.

ALGAE BUNDLEIf the algae are driedproperly, they canbe stored for years.

STARTThe algae are givenan alkaline pH.

WASHINGThey are washed withwater; then acid is added.

COOKINGThe mass iscooked with a pHof 6.5 or 7.

13 feet (4 M)The depth atwhich Sargassois collected.

2 hoursTHE APPROXIMATE LENGTH OFTIME THE ALGAE IS COOKED

POOLThe pool receives themixture free fromrock or shell matter,and a mechanism inthe tank slowly stirsthe mixture.

GELATINcontains 1%agar.

HOT AIR160-175° F(70-80° C)

QUALITYCONTROLSamples aretaken duringsuccessivestages of sifting.

IN MEDICINEAgar has laxativeproperties. Agar is alsoused as a medium forculturing microorganisms.

COLLOIDAlgae extract is soluble only in hot water. It isused to add consistency to dairy products suchas cheese, as well as to other food products.

CRUSHED ALGAEBleaching with saltwater improves itsquality.

REGENERATIONIn order for thealgae to grow back,only 40 percent of itis harvested.

DRYINGPRESS

DRYINGBELT

GRINDING

MOISTGEL

GELLING

PRESS

26 FROM ALGAE TO FERNS

AlkalinizationAfter the dry bundles are gathered, the algaeare transported to an alkaline treatmentpond. There sodium hydroxide (NaOH) isadded, and the mixture is heated to atemperature of 176° F (80° C). The mixture isthen washed and hydrated with cold water.

Washing and BleachingAfter the alkaline treatment algae pass through aprocess in which they are washed with cold water. Toensure an even processing, compressed air is bubbledthrough the water. Later sodium hypochlorite is addedto bleach the algae. Some sulfuric acid can be added tothis mixture to regulate acidity.

2

DryingGel sheets about 0.4 inch (1 cm) widecome out of the press between layers ofnylon. They are placed on platforms, wherethey begin to dry. The sheets are thenplaced on a conveyor belt and furtherdried by a stream of hot air.

4

TransformationAn initial filtering step uses only water anda filtering soil. The mixture must be kept incontinuous motion and injected with steamto prevent it from separating. The mixturethen passes through stainless steel pipes inwhich it is cooled to obtain a gelatin thatcontains 1 percent agar.

3

A World of UsesAlgae extracts are used in the manufacture offood products, medicines, cosmetics, medical

supplies, and even tools. They can serve asemulsifying, stabilizing, thickening, or clarifyingagents. Algae extracts are used in ice cream piefillings, puddings, and salad dressings. They are alsoused for making molds in dentistry, for lubrication indrawing wire, and as a medium for culturing bacteria.

1

The Algae Industry

DulsePalmaria sp.

FinishingGround into a powder, the productmust go through successive millingand sifting steps to eliminate anylumps and impurities. Samples aretaken as the algae product is refined.Once it has passed inspection, thefinal product is packaged.

5

9 pounds(4 kg)THE QUANTITY OF FRESHALGAE NEEDED TO OBTAINABOUT 2 POUNDS (1 KG) OFDRY ALGAE.

per square inch (10 kg/sq cm)150 poundsIS THE PRESSURE AT WHICH HOTAIR IS APPLIED TO DRY THE MASS.

DRY ALGAEProperly processed, gelatin canbe obtained from these algae.

THE AMOUNT A LICHEN CANGROW IN A YEAR.

0.8 inch(2 cm)

CLASSES OF LICHENS EXIST.

15,000THE LIFE SPAN A LICHEN CAN ACHIEVE

4,000 years

PLANTS, ALGAE, AND FUNGI 29I28 FROM ALGAE TO FERNS

Strange Bedfellows

HOW IT IS CREATED

LAYER OF ALGAEThe layer containsgreen algae, whichcarry outphotosynthesis tofeed the fungus.

GONIDIAName given to algaewhen they form partof a lichen

APOTHECIAintervenes in thereproduction of thefungus because itcontains its spores.

CorticolasIn trunksand branches

TerricolasIn the soilof forests

SaxicolaOn rocksand walls.

HAIRSFormed by theends of thehyphae of thecortex or medulla

RICINFixation organs thatarise from the cortexor from the medulla

CORTEXExternal layerof the lichen

MEDULLAMade up offungus hyphae

SOREDIAUnit of lichendispersion, formed bygroups of gonidiasurrounded by hyphae

HYPHAEFungalfilaments, whichare interwovenand colorless

LAYER OF FUNGIThe fungi are generallyascomycetes. Theyprovide the alga withthe moisture it needsto live.

FoliaceousA showy lichen that has theappearance of widely spreadleaves. It is the most commonmacrolichen.

Lobaria pulmonaria

FructicoseThe long-branched thallus is raisedor hanging and can resemble smalltrees or entangled bushes.

Pseudoevernia sp. AlgaCell

1 The spore of thefungus encountersthe alga.

2 The spore growsaround the alga, andthe alga reproduces.

They form a neworganism (thallusof the lichen).

3

Lichens are the result of a close relationship between fungi and algae (usually green algae).Although they are most common in cold areas, they adapt easily to diverse climatic conditions.Lichens can grow in the Arctic glacial regions, as well as in deserts and volcanic regions. They

live on rocks, from which they obtain all the necessary minerals to live, and they contribute to theformation of soils. Lichens are excellent indicators of the level of environmental pollution,since elevated levels of pollution cause them to die.

A Symbiotic RelationshipLichens are the result of symbiosis between afungus and an alga, a relationship from which

both benefit. In a lichen the fungus offers the algasupport and moisture and protects it from heat anddehydration. Likewise, the alga produces food foritself and for the fungus through photosynthesis.

Where They LiveLichens grow in cold regions, as well as in theAmazon Rainforest and the desert. They are very

sensitive to environmental pollution.

CrustaceansWith an appearance of scales,tightly affixed to the substratum,they can be continuous orfragmented in plates or areolas.

0.08 to 0.15 inch(2-4 mm)

0.04 to0.08 inch(1-2 mm)

0.1 to 0.2 inch(3-6 mm)STIPES

The stipes are projections on thesurface of the thallus at whichvegetative multiplication takes place.Their shape is variable, and theircolor may be the same as or slightlydarker than that of the thallus.

IN THE MOUNTAINSThis lichen is commonon the bark ofmountain conifers. Itsthallus looks like horns.

Hypha

GerminatingSpore

Physcia caesia

FUNARIAHIGROMETRICAbelongs to the groupof plants calledbryophytes.

Ovule

Spermatozoids

SPECIES OF MOSSEShave been classified within thebryophite group of nonvascular plants.

10,000

MeiosisMeiosis is a type of cellular division inwhich each daughter cell receives onlyone complete set of chromosomes.Therefore, the resulting cells have halfas many chromosomes as the parentcells had. In general, this mechanismgenerates the gametes, but mossesgenerate haploid spores in the capsuleof the sporophyte.

Capsule

Calyptra

PerichaetiumStalk

Operculum

Rhizoid

Mosses were among the earliest plants to emerge.They evolved from green algae more than 250million years ago and belong to the group of

simple plants called bryophytes. Mosses reproduceonly in environments where liquid water is present.Because they grow in groups, they take on theappearance of a green carpet. Theseprimitive plants can serve asindicators of air pollution, andthey help reduce environmentaldegradation.

Mosses

Small PlantsMosses are bryophytes. They arerelatively small plants that affix

themselves to a substratum via rhizoids andcarry out photosynthesis in small “leaves” thatlack the specialized tissues of the real leaves ofvascular plants. They fulfill a very importantecological role: they participate in theformation of soils by decomposing the rocks onwhich they grow, and they contribute to thephotosynthesis of epiphytes in rainforests.Their asexual reproduction occurs throughfragmentation or the production of propagula.

Operculum A type of cap thatcovers the opening ofthe capsule andnormally separateswhen the spores exit

MatureSporophyteconsists of acapsule inwhichspores areformed.

SPORESThe life cycle of amoss begins with thefreeing of the sporesthat form in thecapsule, which openswhen a cap called theoperculum is expulsed.

ADULTGAMETOPHYTEThis is what agrowngametophytelooks like. GERMINATION

OF THE SPOREThe sporegerminates andgives rise to afilamentousprotonema(cellular mass).

DEVELOPMENT OFTHE SPOROPHYTEThe zygote dividesthrough mitosis andforms thesporophyte, whichremains united tothe gametophyte.ZYGOTE

It forms fromthe union oftwo sexual cellsin a wateryenvironment.

ADULTSPOROPHYTE The adultsporophyte consistsof a capsule (withinwhich the sporesform), a stalk(which holds thecapsule), and a foot.

GAMETOPHYTEDEVELOPMENTThe gametophytegrows.

HORIZONTALFILAMENTSThegametophytedevelops fromthe horizontalfilaments.

Rhizoids

Archegonium:the femalesexual organ

Antheridium:the malesexual organ

DIPLOID

Diploid cells have two sets ofchromosomes. Consequently, theyhave duplicate genetic information.

HAPLOIDA haploid cell is one that contains only onecomplete set of genetic information.Reproductive cells, such as the ova and sperm inmammals, are haploid, but the rest of the cells inthe body of higher organisms are usuallydiploid—that is, they have two complete sets ofchromosomes. In fertilization two haploidgametes unite to form a diploid cell. In the caseof mosses all the cells of the gametophyte, thegametes, and the spores are haploid.

Annulus

Capsulecontains thespores and isfound at the tip.

Sporophyte

Gametophyte

FertilizationReproductive organs that produce gametesdevelop in the green gametophytes, whichlive all year long. When there is sufficientmoisture, the male gamete reaches a femalegamete and fertilizes it. The zygote thatarises from this union grows and formsthe sporophyte. The sporophytepossesses fertile tissue that undergoesmeiosis to generate spores that, afterfalling to the ground and germinating,will form a new gametophyte.

The Cycle of LifeMosses do not have flowers, seeds,or fruits. As with other plants,

mosses have a life cycle formed byalternating generations; however, in contrastwith vascular plants, the haploid gametophyteis larger than the diploid sporophyte. Theirbiological cycle begins with the release of spores,which form in a capsule that opens when a small capcalled the operculum is ejected. The spores germinateand give rise to a filamentous protonema (cellularmass) from which the gametophyte develops. Thezygote that forms from the union of the two sexualcells develops into the sporophyte.

0.2 inch (5 mm)

SPOROPHYTEThe sporophyte does not have an independent existence but lives atthe expense of the gametophyte. The sporophyte lives a short timeand only during a certain time of the year.


INDUSIUMSmall cap that protectsand covers the soriwhile the spores matureinside each sporangium

SPORANGIUMMicroscopiccapsule thatcontains thespores

32 FROM ALGAE TO FERNS

Dispersion of SporesT

he fern is one of the oldest plants. Ferns have inhabited the surface ofthe Earth for 400 million years. Their leaves have structures called sorithat contain the sporangium, which houses the spores. When the sori

dry up, they release the spores into the air. Once on the ground, the sporesgerminate as gametophytes. In times of rain and abundant moisture themale cells of the gametophyte are able to swim to reach femalegametes, which they fertilize to form a zygote that will grow asa sporophyte.

YOUNGPROTHALLUS

ANNULUSRow of cellslocated on theback wall. When itdries, the number ofsporangia doubles.

THIN WALLFormed by asingle layerof cells

FILAMENTunites withthe pinnule inthe placenta.

SPECIES OF FERNS CAN BEFOUND IN THE WORLD.

12,000 BThe lowercell givesrise to athin stalk.

The stalk dividesinto four initialcells and smallsporocytes.

CThe wall of themature sporangiumis formed by a singlelayer of cells.

DIt forms a fixednumber ofspores throughmeiosis.

E

HOW A LEPTOSPORANGIUM IS FORMED

AIt starts as a single initialepidermal cell.

PINNASPetioles intowhich the leafis divided

PINNULESSmaller lobes thatcontain sori on theirinner side

CIRCINATEVERNATIONThe manner inwhich frondsexpand from abud by unfurlingfrom the tip

Catapult of SporesWhen the sporangia dryand wither, they liberatespores through a catapultmechanism.

3

FertilizationThe male and female organsare differentiated in theprothallus. In the presence ofliquid water the antheridiaswim to fertilize the ovule.

5

MaturityWhen the sporophyte ismature, it produces alarge number ofsporangia that grouptogether, forming sorion the back of thesporophyte's leaves.

2

Rachis

Pinnate

Frond

Rhizome

Root

SORIContains thesporangia

PLACENTA

GerminationWhen the spore encounters theright environment, it develops intoa multicellular structure that formsthe haploid gametophyte, calledthe prothallus.

4

300 millionTHE NUMBER OF SPORES ONE FERN LEAF CANPRODUCE. THEIR TOTALWEIGHT IS 0.04 OUNCE (1 G).

SPOREThe spore is

the mosteffective unit of

dispersion because ofits aerodynamic form

and microscopic dimensions.

GAMETOPHYTE

BirthThe zygote develops into astructure called a sporophyte; itis the part visible to the nakedeye. In some cases it has theappearance of a serrated leaf.

1

AntherozoidMaleGamete

OvuleFemaleGamete

AdventitiousRoot

GAMETOPHYTE

Primary Leafof a GrowingSporophyte

SPOROPHYTE

AtheridiumMale SexOrgan

ArchegoniumFemale SexOrgan

Rhizoid

Cellular sheetthat formsthe prothallus

Rhizoid Spore

ENERGY MANUFACTURERS 48-49

FUNCTIONAL BEAUTY 50-51

POLLINATION 52-53

BEARING FRUIT 54-55

CONIFERS 56-57

Seed Plants

Unlike animals, plants arelimited in their ability to seekfavorable conditions for lifeand growth. Consequently,they have evolved in different

ways to reproduce and increase theirpopulation through seeds. A seed mustarrive at an appropriate location at thebest time for germination. Eachspecies achieves its objective in a

different way. Some produce a greatnumber of seeds; others wrap theirseeds in a layer of hard material thatsoftens with rain and winter's cold togerminate in spring. In this chapter you

will find how this process takes place,step by step, from pollination to theformation of a new plant.

SEEDS, TO AND FRO 36-39

UNDER THE EARTH 40-41

STEMS: MORE THAN A SUPPORT 42-43

WOODEN HEART 44-45

GROWTH SPRINGS ETERNAL 46-47

THE POLLEN REACHES THE STIGMAThis is the first step toward forming a seed.In this magnified image the grains of pollencan be seen on the stigma of wolfsbane(Arnica montana).

Reproduction from seeds is the most prominent evolutionary advantage in plants'conquest of the terrestrial environment. The seed shelters the embryo of the futureplant with protective walls. The embryo is accompanied by tissues that provide

enough nutrients for it to begin to develop. Optimal temperature and an appropriatequantity of water and air are the factors that stimulate the seed to awaken to a marvelouscycle of development and growth that will culminate in the generation of new seeds.

Seeds, To and Fro

36 SEED PLANTS

1 Awakening of the SeedSeeds, such as those of the field, or corn, poppy(Papaver rhoeas), leave their latent stage when theyhydrate and receive enough light and air. Theirprotective coverings open and the embryo grows thanksto the energy provided by its cotyledons, or seed leaves.

2 TropismBecause of gravity, amyloplasts arealways located in the lower part ofcells. They produce a stimulus thatencourages the root to grow towardthe earth, a process called geotropism.

WATERis responsible for breakingopen seed covers becausethe hydrated tissues exertpressure on the interior ofthe seed.

PRIMARY ROOTIt anchors itself to theground and branchesout to support theplant in the substrate.

Cell multiplication allowsthe stem to grow.

COTYLEDONThe first embryo leaf.It provides the energyneeded for growth.

AutumTHE TIME OF THEYEAR IN WHICH THESEED OF PAPAVERRHOEAS GERMINATES

The testaprotects theembryo and thecotyledonsduring the seed'slatent stage.

NUTRIENTSThe radicle is incharge of collectingwater and nutrientspresent in the soil.

0.04 in(0.1 cm)

3 in (8 cm)

5 in (12 cm)

6 in (15 cm)

8 in(20 cm)

RADICLEThe embryo rootthat will producethe main root ofthe plant

ABSORBENT HAIRSThese organs begin todevelop in the radicle.They help the seed absorbwater from the soil.

PLUMULEThe bud of aplant embryothat will producethe first shoot

HARD COVERCalled the testa, itcan appear in verydifferent forms.

The root has manyfine hairs that createa large surface areafor water absorption.

SESSILE LEAVESThe upper leaveshave no petiole.

FLOWERINGInternal and externalchanges stimulatethe apical bud todevelop a flower.

Vegetative GrowthThe first true leaves unfold above the cotyledons,and the stem elongates from formative tissue calledthe meristem, located at the apex of the plant.Continued growth will lead to the formation of anadult plant, which will develop its own reproductivestructures.

CONDUCTIONThe stem carries waterand minerals from theroot to the leaves, whiletaking manufacturedsubstances in theopposite direction.

FIRST TRUELEAVES

THE TYPICAL HEIGHT OF ANADULT FIELD POPPY PLANT

20 inches(50 cm)

ALTERNATELEAVES

TOTIPOTENCYCharacteristic ofthe vegetativeapex cells

0.4 inch(1 cm)IS THE MAXIMUNHEIGHT IT CANGROW IN ONE DAY.

HYPOCOTYLThe first part of thestem that emergesand develops in theyoung plant

The cotyledon iscarried by thevertical growth ofthe stem.

APICAL GROWTHLight stimulatesthe multiplicationof cells in the apexof the stem.

Cotyledons canremain under thesoil or, as in thiscase, grow abovethe ground.

3 4

5

GrowthThe seedling grows and breaks through thesurface. This causes the plant to be exposedto light so it can begin to carry outphotosynthesis. It thus begins to manufactureits own nutrients to replace those provided bythe cotyledons.

Production of theFlower's Parts The apical bud begins to producefertile flower structures(gynoecium and androecium) andsterile structures (petals andsepals). The flower bud forms.

SECONDARYROOTS

THE FIRST 20 DAYS OF A FIELD POPPY

EndospermEnzymes

Gibberellin

Nutrients

Seed Cover

Embryo

Gibberellinsare plant hormones that, during the first stages ofgermination following water absorption, are distributed

through the endosperm. Their presence promotes theproduction of enzymes that hydrolyze starches, lipids, andproteins to turn them into sugars, fatty acids, and amino acids,respectively. These substances provide nutrition to the embryoand later to the seedling.


38 SEED PLANTS

POLLEN

Pollination by AnimalsAnimals, especially insects, help theplant disseminate its pollen afterthey enter the flower in search offood. This is one of the mainmechanisms of pollination.

Pollinationby WindWind is an ideal meansfor transporting pollenover long distances.

Stigma

Antera

OvaryNectarium

Bees approach flowers insearch of nectar and carryaway grains of pollen thatcling to their hairs.

Flowering Once the bud opens, the parts of the flower begin to unfold.They are arranged in whorls, or cycles. The whorl called thecorolla contains the petals, and two inner whorls contain thefertile parts of the flower—the androecium and gynoecium.

COMPOSITESThe leaves are verydivided and participatein photosynthesis.

ANTHESISis the name given to theopening of the flower bud.

PollinationThe mechanism bywhich floweringplants reproduceinvolves the dispersalof pollen.

4 inches(10 cm)THE AVERAGE SIZEOF THE FLOWER

FruitThe seeds developinside the fruit. Each seed can developa new seedling.

FRUITAfter fertilizationthe ovary andadjacent tissuesbecome the fruit.

STAMENS

3,000SEEDS CAN BECONTAINED IN ONE RIPEFIELD POPPY FRUIT.

FRUIT

SEEDS

Something in CommonWhen a seed encounters the rightconditions, it can begin its life cycle. Even

though every species of plant with flowers has itsown particular life cycle, the various stages of thecycle represented here are typical of angiospermsin general.

The absorbent hairsare destroyed byabrasion from the soilbut are constantlyrenewed.

SEMILLAS

ALTERNATELEAVES

DispersionThe fruit of a field poppyis a capsule with smallopenings at the top thathelp scatter the seeds.

Ripe FruitThe fruits scatter the seeds.Field poppies have dry fruitsthat open when theymature. This facilitates thedispersion of the seed by air.

SeedEach seed distributed by air,water, or an animal can, underthe right environmentalconditions, germinate anddevelop into a new seedling.

ANDROECIUMIt producesmale gametes.


6

7

8

9

10

11


Types of RootsRoots differ, depending on their origin.The primary root originates in the radicle

of the embryo. An adventitious root is one thatoriginates in any other organ of the plant.Roots are also subdivided according to theirmorphology.

WATERenters throughthe root hairsand travels tothe epidermalcells.

NUTRIENTSdepend on the quantity ofnutrients in the soil and on theroots' ability to transport them.

ROOT STRUCTUREThe root cap is found at oneend. While the root grows, theroot cap protects it from soilabrasion. The interior of theroot is formed by the cortex,which has a compact layer ofcells that affect the flow ofwater through the root. This isdue to the presence of a waxysubstance that forms theCasparian strip.

PROTODERMIS

LATERALMERISTEM

APICALMERISTEM

PROCAMBIUM

ROOT CAPThe thimble-shapedstructure thatprotects themeristem of the tipof the root as itpenetrates the soil

ROOT HAIR

ENDODERMIS

CORTEX

EPIDERMIS

OSMOSISThe process through whichplants absorb water from thesoil. Water penetrates intothe roots when it has agreater concentration in thesoil than in the intracellularenvironment of the root.

LThe root is a plantorgan that is usually foundunder the soil. It has positive geotropism; its

main functions are absorbing water and inorganicnutrients and attaching the plant to the ground.The root is essential for identifying the particularcharacteristics of a plant. The anatomicalstructure of a root can vary, but, because it doesnot have leaves or nodes, it will always be simplerthan that of a stem.

Under the Earth

40 SEED PLANTS

DicotyledonA plant that has seeds with twoembryonic leaves (cotyledons). It has atap root, and the leaves are usuallypetiolated with a reticulated veindistribution. Their internal organizationconsists of open conducting vessels in acircular arrangement.

MonocotyledonsThese plants have embryos with only onecotyledon. Their embryonic root generally hasa relatively short life and is replaced byadventitious roots that grow from the stem.

GEOTROPISM Geotropism, or gravitotropism,is the growth of a plant orparts of a plant in a particulardirection because of thestimulus of gravity. The forceof gravity orients the stemsand their leaves to growupward (negative geotropism),whereas the roots growdownward (positivegeotropism).

GROWTHAREAArea of cellgrowth andelongation

TAPROOTA taproot growsdownward and haslateral secondaryroots that are notwell developed.

FIBROUSThe root system isformed by a groupof roots of similardiameter.

NAPIFORMThe taproot thickens with storedfood and tapersabruptly near its tip.

BRANCHEDThe main root is divided,creating othersecondary roots.

TUBEROUSFibrous instructure, some of the rootsthicken to storefood for the plant.

TABULAR Tabular roots format the base of atrunk and create asupporting buttress.

CASPARIANSTRIP

PLASMAMEMBRANE

OSMOTICPRESSURELess OsmoticPressure

EVAPORATION/TRANSPIRATION PRESSURE

CELL WALL

SUBSTRATE WITHAN EXCESSIVECONCENTRATIONOF SALTS

OSMOTICPRESSUREGreater OsmoticPressure

SUBSTRATEWITH LOWSALINECONCENTRATION

GROWTH ANDCELLULAR DIVISIONThrough the process of celldivision a cell divides into twocells, each with its ownnucleus. The new cellselongate, allowing the root togrow in thickness and length.

PILIFEROUS AREAThe part of the rootcovered withslender elongationscalled roots hairs.The root hairsincrease the surfacearea through whichwater and mineralscan be absorbed.

BRANCHINGAREAA porous regionwhose functionis to anchor andabsorb

NECKTransitional areabetween the rootand the stem

ANTICLINAL(cell divisionperpendicularto the surface)

PERICLINAL(cell divisionparallel to thesurface)

PERICLINAL

ENDODERMIS

XYLEM

PHLOEM

CORTEX

EPIDERMIS

PERICYCLE

CirculationBecause the stem is the link between the roots,which absorb water and minerals, and the

leaves, which produce food, the stem's veined tissuesare connected to the roots and leaves. It functions as atransport system for interchanging substances. Thestem and its branches hold the leaves up to receivelight and support the plant's flowers and fruit. Somestems have cells with chlorophyll that carry outphotosynthesis; others have specialized cells for storingstarch and other nutrients.

ARTICHOKE THISTLECynara cardunculus

Stems have widely varying sizes and shapesthat reflect different adaptations to the

environment. Palm trees and wheat are two goodexamples that show how different mediums canmodify the stem through evolution. Palm trees arethe tallest non-woody plants. They grow tall

because they must compete with many otherplants for sunlight. In contrast, wheat is typical ofareas with a cold climate and a short growingseason. It develops a relatively short stem. Thisenables it to survive the physical assault of the drywind and the loss of leaves.

Stems, which occur in a variety of shapes and colors,support a plant's leaves and flowers. They keep it frombreaking apart in the wind, and they determine its

height. In addition, stems are also responsible fordistributing the water and minerals absorbed by a plant'sroots. Stems contain conducting vessels through whichwater and nutrients circulate. In trees and bushes, stemsare woody for better support.

Stems: More Than a Support

Development of Stems in Different Mediums

NODEA place whereshoots growfrom the stem

42 SEED PLANTS

INTERNODEThe part ofthe stembetween twonodes

SAPWOOD

XYLEMVESSEL

SIEVE TUBE

IN THE WATERThe stem of an aquaticplant can lie underwater.

IN THE GROUNDCertain types ofstems have unusualcharacteristics.

IN THE AIRStems are usuallybranched, as seen in treesand bushes.

TUBERAn underground stemcomposed mainly ofparenchymatic cells filledwith starch. The potato'ssmall depressions areactually axillary eyes. In anonion, another example of aplant with an undergroundstem, starch accumulates notin tubers but in thick leavesthat grow around the stem.

ParenchymaEpidermis

Xylem

Phloem

Sectionof Stem

Sectionof Stem

CROSS-SECTIONOF A NEW STEM

Cuticle

HEARTWOOD

COMPANION CELL

SIEVE PLATE

SIEVE-TUBEELEMENT

Sectionof Stem

LEAF

AXILLAThe jointbetween themain stem anda leaf stem

WATER ANDSALTSare absorbed by the roots and thentransported anddistributed by thexylem in the stem.

CROSS-SECTIONOF STEM

MOVEMENT THROUGH THE STEMIn plants, sugar and other organicmolecules are transportedthrough the phloem, which movesthe sap. The molecules aretransported through sieve tubes.

GLUCOSE Sugar reduces the osmoticpressure in the sieve tubes.

CORE

PHLOEM

CAMBIUM

XYLEM

INNER BARK

PRIMARYPHLOEM

SECONDARYPHLOEM


SPROUTSgrow fromthe eyes.

AXILLARY EYESare grouped in a spiralpattern along the potato.

COMMON POTATOSolanum tuberosum

InitiationThe layer of meristematic cells formed betweenthe xylem and the phloem develops inside thebase tissue until it grows all the way around,forming a cylinder.

Secondary GrowthSecondary growth takes place in the secondary meristems: thevascular cambium and the cork cambium. The vascular cambium isfound between the xylem and the phloem at the end of the plant'sprimary growth zone. It produces secondary xylem toward the insideof the trunk and secondary phloem toward the outside.

PLANTS, ALGAE, AND FUNGI 4544 SEED PLANTS

Wooden HeartE

very year a tree thickens its trunk through the production of growth rings,a process called secondary growth. Each new ring is different from the ringthat grew the year before. This happens because the wood produced over

the course of a year varies in its composition and in the time it takes to form aring. Trees are the largest producers of wood, which can be processed as hand-cutwood, logs, or sawed lumber—the most common form in the industry. To calculatea tree's age scientists study its growth rings.

A Tree's AgeDendrochronology is the study of the age oftrees. The number of growth rings formedsince a tree's birth establishes its age.

INNER BARKis the youngest ring,because a new ring iscreated in each year'sgrowth.

Rolled LogsNot processedbefore use,they are oftenused in ruraland traditionalconstruction.

Hand-Hewn Woodis chopped by handwith an ax. It is usedin rural constructionfor rafters and posts,but it involves aconsiderable loss ofwood.

Sawed LumberIt is cut to specifieddimensions, eithermanually ormechanically, in asawmill. It is the typeof wood most oftenused in construction.

RapidGrowth

SlowGrowth

XYLEMIts main functionis to carry waterand mineral saltsfrom the roots tothe leaves.

OuterBark

SAPWOODis the woody partof the trunk andconsists of xylemtissue. It is pale incolor and ofvariable thickness.

LABURNUMLaburmun sp.

Epidermis

Cortex

Primary Phloem

Inner BarkPrimary Phloem

Primary Xylem

Secondary Phloem

Cortical Parenchyma

Secondary Xylem

Primary Xylem

Vascular CambiumCork Cambium

PHLOEMThe phloem transportsthe products ofphotosynthesis, mostlyin the form of sucrose.This is its main function.

Primary Phloem

Secondary Phloem

Cortical Parenchyma

Secondary Xylem

Primary Xylem

Vascular Cambium

Cork Cambium

SPECIESMost of the 70,000 known treespecies are dicotyledons. However,the oldest trees (4,900-year-oldbristlecone pines [Pinus longaeva])and the tallest trees (360 foot [110m] sequoias [Sequoiasempervirens]) are gymnosperms.The earliest trees known topaleobotany appeared during theDevonian Period.

70,000 Dicotyledons

100Monocotyledons

1,000Gymnosperms

1

TerminationThe veined cambium forms theprimary and secondary vein tissues.

3

LengtheningThe primary xylem and phloem form when the vascularcambium divides.

2TYPES OF WOODWood comes from two main groups of trees:

Wood in angiospermsis the product of theactivity of thecambium and theenvironmentalconditions that existduring the wood'sformation.

The wood of conifers(gymnosperms) tendsto be simpler andmore uniform thanthat of angiosperms.The woody tissueconsists mainly oftracheids.

BranchingGrowth buds can be found at the end of the mainaxis (apical bud) or at the joint where the leavesmeet the stem (lateral bud). Growth can takedifferent forms, depending on the type of bud thatpredominates. If apical buds are more common, thebranch growth is called monopodial. If lateral budspredominate, the branch growth is called sympodial.Conifers are an example of monopodial growth.Sympodial growth is widespread among dicotyledonherbs and is found in practically all monocotyledons.

Lateral BudsThese buds occur on the side of the stem; typically,only one is located in the stem joint. In some casesmany lateral buds are arranged in a series around acolumn (serial buds). They can also be arrangedaround the same crosswise line along the branch orstem (collateral buds).

APICAL BUDThe apical meristem is derivedfrom the embryo and causesthe stem to grow longer. Inseed-bearing plants (divisionSpermatophyta) a group ofmeristematic cells dividesalong different planes,increasing the length ofthe stem.

SHOOTS OFAXILLARY BUDS

GROWTHZONE

LEAF SHOOTSWhen the bractsopen, these smallleaves expand.

MAIN AXIS contains small,compressed nodesand internodes.

SYCAMORE MAPLEAcer pseudoplatanus

InitialCells

Collateral, orAdjacent, Budsare situated one oneither side in the jointof the same leaf,forming a horizontalline. In garlic each cloveis an axillary bud.

SerialBuds

LeafScar

SerialBuds

LeafScar

PHYLLOTAXISis the name of the order of plantswhose leaves are arranged along thenodes of the branches. Each node canhave from one to several leaves.

Arrangementof Leaves

GIANT SEA HOLLYEryngium giganteum

CLARY SAGESalvia sclarea

Serial BudsThese buds are situatedone above the other atthe joint where theprotective leaf meets thestem, forming a verticalfile. The honeysuckle andthe bougainvillea areexamples of this type ofbud.GUM ROCKROSE

Citus ladanifer




Some vascular (veined) plants, also called tracheophytes, are able tocontinue growing year after year. This is made possible by meristems,groups of stem cells that retain the ability to divide. There are two

types of meristems: apical, which carry on the plant's primary growth, andlateral, which give rise to the tissues that increase the plant's girth. As themeristematic cells form new cells, the plant grows and renews its organs.Thanks to their growth buds, the plants maintain their vitality and strengthentheir organs or replace them often. Because of this process, the renewedplants are able to increase their number of branches, flowers, and leaves.

Growth Springs Eternal

46 SEED PLANTS

BRACTSProtective leaves that containgummy substances, whichkeep the bud from drying out

STEM APEX

Apical buds can remain dormant for longperiods of time. With the right physiologicaland environmental conditions, they can awakenand unfold.

The bractshave a scalyappearance.

NEW LEAVESunfold, and growthagain occurs in thegrowth zone.

PROPHYLLSThe first leaves to form

Without BractsSome buds, such as those inplants of the cabbage family(Brassicaceae), are not coveredby bracts. Instead, thevegetable's growth zone iscovered by outer leaves.

INFRAPETIOLAR BUDThe axillary bud is joined to the petiole of a leaf.The growth of the leaf carries the bud outward.This often occurs in plants with inflorescences,or flowers that grow on branches.

SUPERPOSED BUDThe axillary bud is joined to the stem. Asthe cells of the internode multiply, theycarry the axillary bud, which then appearsto be inserted above the leaf.

OPPOSITETwo leaves per node.They are arrangedperpendicularly toearlier and laternodes.

ALTERNATINGOne leaf per node,arranged alternatelyin successive nodes.Found in monocotsand dicots.

VERTICILATESeveral leaves pernode. Whorls areformed in a spiralarrangement aroundsuccessive nodes.

Stem Stem Stem

Leaf ShootsA lengthwise cross-section of a bud showsthe curving and overlapping leaf sproutsthat protect the bud's growth zone.

Awakening

1 The stomatic apparatus isclosed. No air can enter orleave the leaf. This preventsexcessive transpiration, whichcould damage the plant.

2 The stomatic apparatus isopen. The stomatic cells areswollen. As tensionincreases, the cellular formis modified and is able toexchange gases.


Energy Manufacturers

ACER SP.

This genus includestrees and busheseasily distinguishableby their opposite andlobed leaves.

48 SEED PLANTS

VEINSFlowering plants (divisionAngiosperma) are oftendistinguished by the typeof veins they have: parallelveins in monocots andbranching veins in dicots.

TENDRILSThe leaves of climbingplants, such as thegrapevine, have theseadaptive modifications.

CONIFERSNeedle-shaped leavesare characteristic ofconifers. They areusually oval ortriangular. Ahypodermis, which isenclosed by theepidermis, is brokenonly in the stomas.

Change and Its AdvantagesConifers possess an interesting modification in their leaves. In thesegymnosperms evolution directed the abrupt reduction of surface foliagearea. This gave them an adaptive advantage over plants whose leaveshave a large surface area: less resistance to wind and less transpirationin arid climates. In addition, they are able to avoid the excessive weightthat would result from the accumulation of snow on large leaves.

CROSS-SECTIONIn general, upon sectioning a

leaf, one can observe that it

possesses the same tissues as

the rest of the body of the

plant. The distribution of tissues

varies with each species.

PLANTS AND THE ENVIRONMENTThe flow of carbon dioxide and water vapor

between the plant and the environment is

essential for the photosynthetic process. This

exchange can be affected by internal or

external factors, such as changes in light,

temperature, or humidity. In response to

these stimuli the stomas can open or close.

Simple LeavesIn most monocotyledon plants theleaf is undivided. In some cases it mayhave lobes or notches in its side, butthese divisions do not reach all theway to the primary vein of the leaf.

Compound LeavesWhen the leaf is divided from the primary vein, itforms separate leaflets. A compound leaf is calledpalmate when the leaflets are arranged like thefingers on a hand and pinnate when they grow fromthe sides of the leaf stem like the barbs of a feather.

The main function of leaves is to carry out photosynthesis. Their shape isspecialized to capture light energy and transform it into chemicalenergy. Their thinness minimizes their volume and maximizes their

surface area that is exposed to the Sun. However, there are a great manyvariations on this basic theme, which have evolved in association with differenttypes of weather conditions.

EDGES (MARGINS)Species are distinguishedby a wide variety of edges:smooth, jagged, and wavy.

LEAF STEM(PETIOLE)

RACHIS

CONDUCTING TISSUEis made of live cells(phloem) and dead cells(xylem).

BASIC TISSUEis formed by live cells thatgive structure to the leafand usually contain somechloroplasts. EPIDERMAL TISSUE

is composed of live cells. Itsurrounds all the parts ofthe leaf and the plant. Itproduces a substance thatforms the cuticle.

PRIMARY VEINS The products ofphotosynthesis circulatethrough the veins fromthe leaves to the rest ofthe body.

LEAF SURFACEColorful, usually green,with darker shades onthe upper, or adaxial,side. The veins can bereadily seen.

EPIDERMIS Cells with thickwalls and athick cuticle

RESINfunctions toprevent freezing. Itcirculates throughthe resin ducts.

VASCULAR BUNDLEFormed by phloemand xylem

Cellulose Microfibers

Thickened cell walls in thearea of the pore

PLANTS, ALGAE, AND FUNGI 5150 SEED PLANTS

Functional BeautyF

lowers are not simply beautiful objects; they are also the place where thereproductive organs of angiosperms are located. Many are hermaphroditic,meaning that they contain both the male reproductive apparatus (the

androecium) and the female (the gynoecium). The process of pollination is carriedout through external agents, such as insects, birds, wind, and water. Followingfertilization, flowers produce seeds in their ovaries. The floral parts arearranged in circular or spiral patterns.

WhorlsMost flowers have four whorls. In a typical flower theoutermost whorl is the calyx, followed by the corolla, the

androecium (which can have two parts), and the gynoecium.When a flower has all four whorls, it is considered complete; itis incomplete when it lacks at least one of them. Plants thathave an androecium and a gynoecium, but in separate flowers,are called monoecious. If the flower lacks a sepal and petals, itis said to be naked.

ClassificationPlants with flowers are classified as dicotyledons ormonocotyledons. The first group has seeds with two cotyledons,

and the second has seeds with only one. Each represents a differentevolutionary line. They are differentiated by the structure of theirorgans. The cotyledon contains nutrients that the embryo utilizesduring its growth until its true leaves appear. When a seed germinates,the first thing that appears is the root. In monocotyledons the stemand the radicle are protected by a membrane; the dicotyledons lackthis protection, and the stem pushes itself through the soil.

DicotyledonsIn this class of plants each whorl of the floweris arranged in groups of four or five parts. Indicotyledons the sepal is small and green, thepetals are large and colorful, and the leaves arewide. The vascular ducts are cylindrical.

MonocotyledonsEach whorl of these flowers contains threeparts, and their sepals and petals aregenerally not differentiated from oneanother. The majority are herbaceous plantswith scattered vascular conduits. They arethe most evolved species of angiosperms.

COROLLAA grouping of petals. If itsparts are separated, theyare simply called petals; ifthey are united, the plant isdescribed as gamopetalous.

CALYXThe grouping of sepals that protects the other parts of theflower. Together with the corolla it forms the perianth. Thesepals may be separate or united; in the latter case the plantis called gamosepalous.

OVARYThe ovary is found inthe receptacle in thebase of the gynoecium,inside the carpels. Thepollen tube, whichconducts the pollen tothe ovule, extends tothe ovary.

AndroeciumThe male reproductive system. It isformed by a group of stamens, each of which consists of an anthersupported by a filament. The base maycontain glands that produce nectar.

STIGMAIt can be simple ordivided. It secretes asticky liquid that capturesthe pollen. Some are alsocovered with hair.

GynoeciumThe female reproductivesystem. It is formed bycarpels and includes theovary, ovules, style, andstigma.

ROOTIn monocotyledonsall the roots branchfrom the same point,forming a kind ofdense hair. They aregenerally superficialand short-lived.

ROOTIn dicotyledons themain root penetratesthe ground verticallyas a prolongation ofthe stem, andsecondary roots extendfrom it horizontally. Itcan be very deep andlong-lived.

LEAVESIn dicotyledons,leaves havevarious forms, andthey contain anetwork of veinsthat connect witha primary vein.

CARPELThe carpel consists of modified leavesthat together form the gynoecium. Itcontains a stigma, a style,and an ovary. Ovulesare produced inthe ovary.

STYLESome styles are solid,others hollow. Theirnumber depends onthe number of carpels.The pollen tube growsthrough the style. Incorn the tube canreach a length of 15inches (40 cm).

SEPALEach of the modifiedleaves that protect theflower in its first stage ofdevelopment. They alsoprevent insects fromgaining access to thenectar without completingtheir pollinating function.Sepals are usually green.

TEPALIn monocotyledonous plants the petalsand sepals are usually the same. In thiscase they are called tepals, and the groupof tepals is called a perianth.

FLORALDIAGRAM

FLORALDIAGRAM

OVARYThe ovary is found in the receptacle atthe base of the gynoecium, inside thecarpels. The pollen tube extends intothe ovary and penetrates the ovule.

LEAVESPlants with only onecotyledon have largeand narrow leaves,with parallel veinsand no petiole.

THE NUMBER OF KNOWN SPECIESOF ANGIOSPERM PLANTS, THOUGHONLY 1,000 SPECIES HAVEECONOMIC IMPORTANCE. ABOUTTWO THIRDS OF THESE SPECIESARE NATIVE TO THE TROPICS.

250,000FILAMENTIts function isto sustain theanther.

ANTHERA sac wheregrains of pollen(the malegametes) areproduced

PETALIt typically has ashowy color to attractpollinating insects orother animals.

PollinationT

he orchid, whose scientific name Ophrys apifera means “bee orchid,”is so called because of the similarity between the texture of itsflowers and the body of a bee. Orchids' flowers are large

and very colorful, and they secrete a sugary nectar that iseaten by many insects. The orchid is an example of azoomophilous species; this means that its survivalis based on attracting birds or insects thatwill transport its pollen to distant flowersand fertilize them.


TransferThe bee takes off towardother flowers, with pollenfrom the orchid stuck toits back.

4

Toward aDestinationWhen it arrives at another flowerof the same species, the beerepeats the incursion and bumpsthe flower's stigmas (femaleorgans), depositing pollen that iscapable of fertilizing it.

5

The LoadWhile passing through

the narrow tunnel,the bee brushes the

pollinarium, andpollen sticks tothe bee.

3

AttractionWhen a flower opens, aliquid drips on its lowerpetal and forms a smallpool. The liquid gives offan intense aroma thatattracts bees.

1

The FallExcited by the perfume and the texture, the bee entersthe flower, and in thispseudo-copulation itusually falls into thepool and becomestrapped. It cannot flyand can only escapeby climbing theflower's stamens.

2

Bee OrchidOphyrys apifera

POLLINIUMA small clump of closely packedpollen grains

CAUDICLEAt times itcloses, coveringthe pollinia.

CORBICULUMOrgan for thetransport of pollen

LABELLUMIts form imitatesthe abdomen ofthe bee.

ODORThe odor issimilar to beepheromones.

NECTARA sugaryliquid that issomewhatsticky

LOBULESThey have fine, silky hairsthat attractthe bees.

POLLINATINGINSECTMale BeeGorytes sp.

COLORATIONis one of thefactors ofattraction.

Each grain contains a male gamete.

Pollen

12,000THE NUMBER OF SEEDSTHAT A SINGLE FERTILIZEDORCHID PRODUCES

CAMOUFLAGESome plants that rely on insects forpollination acquire the appearanceof the animal species on which theydepend for survival. Each orchid hasits own pollinating insect.

52 SEED PLANTS

POLLINARIUMGrouping of two, four,six, or eight pollinia

0.008 to0.08 inch(0.2-2 mm)

POLLINIASmall clumps ofpollen grains housedin a compartmentof the anther

GRAIN OFPOLLEN

Bearing Fruit

54 SEED PLANTS

Simple Fruitscome from a single flower. They may contain one ormore seeds and be dry or fleshy. Among them aredrupes, berries, and pomes.

PeelIt consists of the mesocarp and exocarpof the fruit. It is soft and secretes oilsand acids. However, in the case of a nut,its hard “peel” is its endocarp.

SectionA sac that fills with juices(reserves of water and sugar)produced by the ovary walls

POMESare fleshy fruits that come from epigynous flowers,or flowers whose enclosed ovaries lie below theplace where the other parts of the flower areattached. The floral receptacle thickens and formsan edible mesicarp. Apples are one example.

A

C BERRIESWhen they mature, berries generally have a brightcolor and a fleshy or juicy mesocarp. They comefrom either epigynous or hypogynous flowers. Thegrape is an example.

FIGCondensed fruit

BLACKBERRYIn this aggregate fruit,each berry is a fruit.

DRUPESare fleshy fruits, leathery or fibrous, which aresurrounded by a woody endocarp with a seed in itsinterior. They are generally derived fromhypogynous flowers—flowers whose ovaries lieabove the point where the other flower parts areattached. An example is the peach.

B

Multiple Fruitsare those that develop from the carpels ofmore than one flower, in a condensedinflorescence. When they mature, they arefleshy. An example is the fig.

AGGREGATE FRUITThe fruit is made ofnumerous drupelets thatgrow together.

A SYCONIUMThe fruit axis dilates andforms a concavereceptacle with the shapeof a cup or bottle.

B

Dry Fruitsare simple fruits whose pericarps dry asthey mature. They include follicles

(magnolias), legumes (peanuts, fava beans, peas),pods (radishes), and the fruits of many otherspecies, including the majority of cereals and thefruits of trees such as maple and ash. Mostdehiscent fruits (fruits that break open to exposetheir seeds) are dry fruits.

OrangesLike other citrus fruits,oranges are similar toberries. Their seeds maypropagate when thefruit rots and exposesthem or when an animaleats the fruit and thendefecates the seeds.

14%THE PROPORTION OF ANIMMATURE CITRUSFRUIT THAT IS MADE UPOF THE FLAVONOIDGLYCOSIDE (HESPERIDIN)

EXOCARPThe skin, or externalpart, of the fruit

MESOCARPA fleshy structure that isrelatively solid

ENDOCARPThe part of the pericarpthat contains the seeds. Itis formed in parts, orsections.

Loculos

Vesicles

AbortedSeeds

Seeds

CentralAxis

Septos

OvaryWalls

Pulp

Seed

Endocarp

Pulp

Seed

Pulp

Skin

Seed

ENDOCARP

EXOCARPMESOCARP


Once the flower is fertilized, its ovary matures and develops, first toprotect the seed forming within it and then to disperse the seed.The stigmas and anthers wither, and the ovary transforms into

fruit. Its wall forms the cover, or pericarp. Fruits and seeds are ofgreat economic importance because of their key role in humannutrition. The endosperms of some seeds are rich in starch,proteins, fats, and oils.

Are effectively the most representative of the gymnosperms, a groupof plants with seeds but not flowers. Through the fossil record itis known that conifers have existed for more

than 390 million years. Their leaves are usuallyneedle-shaped and perennial. They are woodyplants that reproduce by means of seeds thatcontain tissues and an embryo that grows untilit becomes an adult plant.

Conifers

Good WoodThe great majority of conifers are evergreens,although some, such as larches (tamarac), are

deciduous. Conifers are the tallest and most long-lived trees,and they provide most of the wood used in industry. Mostconifers form new shoots during the summer. They producea resinous substance that protects them from freezingduring winter. This adaptation permits vital nutrients tocontinue to circulate through their vascular systems, even invery cold weather.

56 SEED PLANTS

MATURE CONE

Three years after thecone appears, its seedsare ready to disseminate.

LEAVESGrouped in sets of two,they have elongatedshapes. They carry outphotosynthesis.

CONES

The male and female conesare generally not locatedon the same branch.

FEMALE CONE

Small and light, it islikely to be pollinatedas soon as it appears.

YOUNG LEAVES

are covered by aprotective capsule.

Pine ConesThe female cone contains ovulesthat are situated among its

ovuliferous scales. The cones are woodyand are usually found in the upperbranches of the tree. The male cones arenot woody and are usually found in thelower branches. When the ovules of afemale cone are pollinated, the resultingseeds need about three years to matureinside the cone. Mature ovules arepopularly called pine nuts.

DISPERSIONThe ovuliferous scalesgenerate a greenishgelatin containing thefemale gametes. Thegametes are freed whenthe sac that contains themopens. A forest fire canpromote reproduction bycausing the sac to open.

Bract Scale

Cuticle

Gametophyte

OvuliferousScales

BractScales

LEAFLET SCALE

ClassificationThe name “conifer” is sometimes erroneously believed toderive from pine trees' conical shape. In reality, thereare other forms of coniferous plants.

ARAUCARIAAraucariaceae

PINEPinaceae

CEDARTaxodiaceae


CLOSED OPEN

Pine NutsPine nuts have long been used with honey andsugar to make pastries. When summer arrives,

harvested pine cones are placed in the sun, which causesthem to open. The pine nuts are then shaken loose fromtheir cones and gathered. In traditional processing thepine nuts are soaked in water to remove their outercovering, which floats to the surface. The pine nuts arethen run between two closely spaced mechanical rollersto crack their inner shells. Finally, the pine-nut meat isseparated from the shell by hand.

14° F (-10° C)OR LESS: TYPICAL AVERAGEJanuary temperature across the extensiveconiferous forests of the Northern Hemisphere.

HEALING OR HARMFUL? 70-71

TOMATO FACTORIES 72-73

OLIVE OIL 74-75

FROM TREE TO PAPER 76-77

HEALING PLANTS 78-79

How does a carnivorous planthunt an insect, and what typeof traps does it use? Why domany plants have thorns orsecrete venomous juices, while

others grow on the trunks of trees or onthe side of rocks? The truth is that inorder to survive in harsh environments,such as places that are extremely dry orcold or places with nutrient-poor soil or

herbivorous animals, plants have had tobecome very strong and develop anumber of strategies for survival, whichwe will tell you about in this chapter.You will also find detailed information

about where the paper that we use dailycomes from, as well as learn about theproduction of tomatoes and olive oil,essential elements in the human diet.

Rare and Useful Plants VENUS FLYTRAPThe most commoncarnivorous plant. It isconsidered to be anactive trap.

TRAPPERS 60-61

HANGING FROM OTHER PLANTS 62-63

DANGEROUS RELATIONSHIPS 64-65

INFLORESCENCES 66-67

BETWEEN WIND AND SAND 68-69

Trappers

The Terror of the FliesThe exotically named Venus flytrap is a famouscarnivorous plant. It produces a nectar that attracts

flies. Reaching the leaf is usually fatal for the visiting insectbecause it sets off a series of physiological reactions in theplant that transform it into a deadly trap. Even largerinsects, such as the dragonfly, can be trapped by thesecarnivorous plants. Upon contact by its prey, a very specificreaction takes place. Hairs detect the presence of the insectand stimulate the closure of the leaves. However, a Venusflytrap's leaves do not react to other types of contact, suchas the impact of raindrops.

Main Menu: InsectsThere are distinct orders of dicotyledonsthat include carnivorous plants, such as

Nepenthales, Sarraceniales, and Scrophulariales.These plants include the pitcher plant, sundews,and bladderworts.

60 RARE AND USEFUL PLANTS

2No ExitThe fold of the leaf stimulatesthe lateral thorns on its oppositesides to interlace like the fingersof two hands and create a typeof cage. This process occurs intwo tenths of a second, so thefly has little chance of avoidingbeing trapped.

DETECTOR HAIRSare sensitive tocontact with insects.

LOWER PART OF THE LEAFThe cells have agreat number ofchloroplasts.

1Falling into the TrapThe fly positions itself above the trap andbrushes the lateral thorns. This stimulusprovokes the swollen cells of the hinge to losewater rapidly, which in turn causes the upperpart of the leaf to close. If the insect is slow toreact or move as the trap begins to close, it willbe unable to escape.

A Varied DietTrappers belong to the group ofautotrophic organisms—that is, they

can produce organic material to use as foodfrom simple inorganic substances.Carnivorous plants live in environments poorin nutrients. The insects that they trappermit them to make up for this deficiency.

CARNIVOROUS PLANTS

DIONEA MUSCIPULA Flytraps are cultivated all overthe world. They are grown inslightly acidic soils, such aspeat. They flourish if they havemany insects to consume.

UTRICULA VULGARISThese aquatic carnivores areof the family Lentibulariaceae.Their leaves are oval vesiclesthat open and close to trapmicroscopic animals.

DROSERA CAPENSISTheir ribbonlike leaves arecovered in sticky hairs. Whenthe leaves receive a stimulus,they roll up and enclose the prey.

DARLINGTONIA SP. Unlike other carnivorouspitcher plants in which thepitcher (trap) is attached to astalk, this plant's pitchergrows directly from the soil.

SARRACENIA SP. These plants are passive trapsthat use nectar to attractinsects. Full of hairs, thepitchers retain the prey andkeep it from escaping.

NEPENTHES MIRABILISThe cover of its leaf-pitcherprevents water from entering.These plants tend to have veryshowy colors that are a fatalvisual attraction to an insect.

Dionaea muscipulaScientific name of the Venus flytrap. It is native to theeastern United States.

LATERAL THORNSare the hardenedborders of the leaves,which have a thickcuticle.

UPPER PART OF THE LEAF

Reniform, or kidney-shaped, it has special

cells arranged along acentral hinge.

3DigestionIn less than three minutes the trap hascompletely closed, and the digestion of theprey's tissue begins. Special glands located in theinterior part of the upper leaf secrete acids andenzymes that chemically degrade the soft partsof the insect's body. When the leaf-trap reopensafter a few weeks, the wind blows away theparts of the exoskeleton that were not digested.

1/5 secondTHE TIME NECESSARY FOR THE UPPER PART OFTHE LEAF TO CLOSE AFTER A FLY LANDS ON IT.

These carnivorous plants are the most exotic in the entire plantkingdom. Their name is associated with their ability tocapture insects and digest them. What do they get from

these tiny animals? They get substances rich in nitrogen, which isusually absent from the soil where they grow. By eating insects,they are able to compensate for this nitrogen deficiency becausethe bodies of the arthropods they catch have amino acids andother nutrients that contain nitrogen.

PLANTS, ALGAE, AND FUNGI 6362 RARE AND USEFUL PLANTS

Hanging from Other Plants

ROOTSThey are in chargeof attaching theplant to thesubstrate, but theydo not absorbwater or minerals.

BULBThe stalk is veryshort or nonexistent.They are herbs thatform rosette-shapedbulbs with theirleaves.

LEAVESFew and leathery.They are covered inabsorbent hairs.

FLOWERIt has the form of atube, and its colorranges from red toviolet. There may beup to 14 flowers ineach inflorescence.

FRUITSFusiform. They measure1.5 inches (4 cm) inlength and barely 0.15inch (4 mm) indiameter. They containfeathery seeds thatdisperse with the wind.

A Different LifestyleBromeliads' roots do not absorb water. Theirhard leaves can capture water and nutrients

from the air. Using a sticky substance, they usuallyattach themselves to the branches of trees, wherethey can have access to sunlight. These traits makeit possible for the them to subsist in their naturalenvironment.

Special LeavesThe best-known function of these plants' leaves is to absorbwater. In addition, at night they incorporate carbon dioxide and

fix it into organic acids. This strategy diminishes their water lossthrough transpiration during the day through the opening of thestomas for gas exchange. When sunlight is available, photosynthesistakes places. The plants are able to manufacture carbohydrateswithout opening their stomas, because they can use the carbon dioxidethat they took in during the night.

These plants are recognized for their bulbs,which have the shape of a small rose, andfor their triangular leaves, which are denselycovered by hairs. The purple lilac color ontheir petals is also very characteristic.

SPECIAL SIGNS

The common origin of thebromeliads is Mexico and thecountries of Central and SouthAmerica. Today bromeliads arecultivated all over the world.

FROM THE NEW WORLD

2.5 to 16 inches(6-40 cm)

Leaves3.5 to 5 inches (9-13 cm)

1.4 to 1.6 inches(3.5-4 cm)

Inflorescences inthe Form of a Spike

Mexico

Guatemala

El Salvador

Honduras

Malic Acid

PyruvicAcid

CUTICLE

CARBON DIOXIDEenters during the night.

GUARD CELLopens only atnight.

MESOPHYLLCELLS

DAYLIGHT

PRODUCTSPhosphoglyceridesthat can formglucose

Carbondioxideis freed.

CALVIN CYCLE

MEDUSA'S HEADTillandsia caput medusae

The epiphytes are a very interesting group of plants. They grow on living or dead treetrunks, surfaces of rocks, wall nooks, and even utility poles and wires. Mosses,ferns, orchids, and bromeliads are among the best-known epiphytes.

Bromeliads are native to the tropical and humid regions of the Western Hemisphere.They are of special interest because they exhibit evolutionary adaptations thatfavored their ability to live without contact with soil. They therefore have novelstrategies for obtaining the water, minerals, carbon dioxide, and light thatthey need to survive.

Like a VampireDodder, a plant of the Cuscuta genus, parasitizes its host by insertingitself into the host's vascular system and sucking out its nutrients.

These parasites do not contain chlorophyll, and their leaves appear as smallscales. Dodder germinates on the ground. It then grows around the stalk of ahost plant and inserts small rootlike projections, called haustoria, into thestalk. As dodder grows, its many filamentous stems can look like spaghetti.Dodder kills herbaceous plants and debilitates woody ones. It is usuallyconsidered a pest because of the economic losses it produces in fodderplants such as alfalfa.Deadly Embrace

The genus Ficus has some lethal plantsamong its members. The epiphyte species of

the genus, during its young stage, can strangulateand kill the tree on which it supports itself. In thisway it can reach the sunlight, which is typicallyscarce on the forest floor. For example, the stranglerfig (Ficus nymphaeifolia), which reaches 23 to 115feet (7-35 m) in height, produces seeds that can

germinate on the branches of another tree. Thispermits it to grow to a tree of great size thatdevelops an extended crown of long, strongbranches. Its roots descend to the ground along thetrunk of the host tree and fuse together, forming athick lattice. The distinct varieties of trees of theFicus genus are characteristic of the rainforests ofthe intertropical zone. Many are of American origin.

PLANTS, ALGAE, AND FUNGI 6564 RARE AND USEFUL PLANTS

Dangerous RelationshipsD

uring their life cycle some plants become a true danger to otherplants. There are groups of epiphytes that, in their quest to reach thesoil and turn into trees, are capable of strangling and killing the tree

on which they begin to grow. Additionally, some plants behave like parasitesor semi-parasites. When the seeds of these plants germinate and theirembryos have used up their energy reserves, they continue to grow becausethey obtain food from their hosts.

WITHOUT CLOROPHYLLThe stalk and the leaves of theseplants do not have chlorophyll; inaddition, their leaves are very small.

DODDERIt forms a genus, Cuscuta, ofbetween 100 and 170 species ofparasitic plants that are yellow,orange, or red.

Upon coming into contact withits host, the vine begins todevelop haustoria. They willgrow and penetrate the stalk ofthe host to reach its vasculartissues (xylem and phloem).

After germinating,dodder's stems climband coil around thestalk of the host untilthe haustoria develop.

The products ofphotosynthesiscirculate throughthe phloem, wherethey are accessedby the haustoria.

The evolution of plants, like thatof living beings in general, hasfavored the rise of the secondaryadaptations shown here. Theseadaptations have benefitedcertain species with notablecharacteristics, such asparasitism. The distinctive traitin these plants is the absence ofconductive vessels.

EvolutionaryPressure

IMPRISONEDThe aerial roots of the straggler

fig move toward the ground,perhaps as the result of

geotropism. As the roots grow,they merge together andimprison the host tree.

SICONOThis type of infructescence isa pyriform receptacle, hollowand with an apical opening. Inits internal walls smallberries, commonly calledseeds, are found.

EUROPEAN MISTLETOEThe birds that eat mistletoefruits disperse the seeds,which are sticky and attach toother trees.

It has chlorophyll but no roots. Itparasitizes the branches of a tree,

disguising itself as just another branch.Mistletoe appears in places like semi-abandoned olive groves. It is native to humid

zones and mountainous areas. The parasitedebilitates the host and makes it morevulnerable to insect attacks. The host treesmay be killed by the mistletoe or by diseasesthat attack the tree in its weakened state.

Mistletoe

1

3

2

Inflorescences


SunflowerIts inflorescence is a headmade of two types of flowers:peripheral florets, which arerayed and unisexual, and diskflorets, which are tubular andhermaphroditic.

PERIPHERAL FLORETSRayed and unisexual

FLOWERScan be fertilizedonly by insects.

DISK FLORETSTubular andhermaphroditic

19 feet (6m)IS THE MAXIMUM HEIGHT OFSUNFLOWERS. THEIR AVERAGEHEIGHT IS 10 FEET (3 M).

20,000THE NUMBER OFCOMPLEX PLANTSPECIES THAT EXISTIN THE WORLD

FLAT LEAVESBroad, oval, opposed,serrated, and rough tothe touch; asperous

BRACTS

STIGMA

STYLE

POLLEN

ANTHER

NECTAR

DISKFLORETS

DOME

OVARY

BRACTS

PEDUNCLE

MEDULLA

EPIDERMIS

PERIPHERALFLORETS

PERIPHERALFLORETS

Types of InflorescencesMost inflorescences correspond to branching in whichthe axis grows in an indeterminate manner, and the

flowers open in order from the base of the axis toward theapical meristem. There are also determinate inflorescences, inwhich the end of the axis bears the first flower, and flowersfarthest from it open last.

RACEMEThe flowers develop onshort stalks, calledpedicels, along anunbranched axis.

SPIKEThe flowers formdirectly from thestem instead offrom pedicels.

CORYMBThe pedicelsare of varyinglengths.

CATKINSimilar to a hangingspike, its flowers areentirely male or female.

UMBELA group of pedicelsspread from the endof the flower stalk.

COMPOUND RACEMEThe flower stalks arebranched.

COMPOUND UMBELThis form is morecommon than thesimple umbel.

SPADIXIt features a spikewith a fleshy axis anddioecious flowers.

HEADThe flowers siton a broad,shortened axis.

DAISYThe daisy is a composite flower. As with thesunflower, what appears to be a single flower is,in fact, an inflorescence called a head. The headcontains a large number of individual flowers,which are attached to a base called a receptacle.

LEAVES OR FLOWERS?All flowers are modified leaves with bright colorsand attractive forms that carry out a veryspecific function: attracting pollinators.

Flowers withAnthers Ready toRelease Pollen

ModifiedLeaf

Ovary

Style

Internal andImmature Flower

BilobedStigma

TubularCorolla

TubularCorolla

Ovary

AntherPollen

Inflorescences consist of clusters of flowers on a branch or system of branches.They can be simple or complex. They are simple when a flower forms onthe main axis in the axil of each bract. They are complex when a partial

inflorescence is born in the axil of the bract that also carries bracteoles orprophylls. Simple inflorescences include racemes, spikes, panicles, catkins,corymbs, and heads. Complex inflorescences include double racemes,double spikes, and double umbels.

The family Cactaceae has 300 genera and thousands of plant species that inhabitpredominantly hot and dry places. Cacti are the best known of these species.They have spines that developed to minimize water loss and to provide

protection against herbivores. Although cacti originated in the WesternHemisphere, they have spread to other parts of the world. Cacti producenectar, which plays an important role in pollination by attractinginsects and birds to their flowers.


Echinopsis pentlandi


FRUITGenerally fleshyberries. In somecases, however,the fruit is dry.

STEMIt is succulent and stores a largequantity of water. It containschlorophyll and is wherephotosynthesis takes place.

LEAVESIn place of simple and alternateleaves, they have thorns, whichprevent water loss throughtranspiration and are a defenseagainst attacks from animals.

AREOLEAxil bud thatgenerates a veryshort branchingof spines

CLADODEPhotosynthetic stem,often succulent, thathas the ability tostore water

OF PLANTS MAKE UP THEFAMILY CACTACEAE.2,000

Between Wind and Sand

GreenIn the absence of greenleaves, photosynthesistakes place in the stem.

DisguisedEpiphyllum cacti do nothave leaves, so the stemsperform their function.

AccordionThey are curvy andexpand when theytake in water.

Cactaceae Stems

DistributionCacti are found in deserts orvery dry climates. They have alsoadapted to the dry and warmclimates of Australia, theMediterranean, and East Africa.

ADAPTING TO THEENVIRONMENTOne of the main characteristics ofCactaceae is their ability to resistdrought by storing water. Their rootsusually extend only a short distanceinto the ground, which allows themto better absorb occasionalrainfall. Some roots grow towardthe surface in order to collectdew. Their skin is covered withwax, which makes it tough andwaterproof and helps preventwater loss.

CRASSULACEAN ACIDMETABOLISM (CAM)Carbon dioxide is taken in at nightand stored as organic acids. Theplant is therefore able to avoidwater loss by closing its stomasduring the day, when it carries outphotosynthesis.

GOLDEN BARRELCACTUSEchinocactusgrusonii

THICKENEDSTEMWater storage

VASCULARCYLINDERTransporttissue

FLESHYROOTWater storage.

SANDY SOILTissue wrapping.

THICKEPIDERMISAlmost poreless;avoids transpiration

THEY RANGEFROM CANADAALL THE WAYTO SOUTHAMERICA.

species

PPLANTS, ALGAE, AND FUNGI 7170 RARE AND USEFUL PLANTS

Healing or Harmful?P

oisonous plants are the type that no one wants in the garden.Although some plants have healing properties, others havesubstances that, when they enter the body, provoke noxious

reactions that cause injury or even death. The most infamous ofthese plants is hemlock, which can also be used medicinally. Theprimary active components of poisonous plants are alkaloids. One of the most potent poisons from plants is ricin: 0.35 ounce (1 mg) is enough to kill a person.

Several cultivated and wild plants have activeingredients that have various levels of toxicity for

people and animals. The castor bean (Ricinus communis)contains ricin, and chewing two of its seeds can be fatal fora child. Digitalis contains substances that can cause a heartattack. Other common poisonous plants, such as oleanders,provoke diarrhea, nausea, and other symptoms if theirflowers or fruits are eaten.

Other Poisonous Plants

Poison is a substance that produces illness or tissue lesions or that interrupts natural vital processes when it comes into

contact with the human organism. Dosage is a key factor for a substance to act as a poison. The same substance that can producedeath in an organism can, in smaller concentrations, act as a medicine and provide relief from certain types of suffering.

A Matter of Quantity

Hemlock Water DropwortOenanthe crocata

SOCRATESThis philosopherdied by drinkinghemlock, asentenceimposed by theGreek court.

WAR FLOWERIt is said thatbelladonna was usedto poison MarkAntony's troops duringthe Parthian wars.

IDENTIFICATIONIn winter the planthas no leaves butgreenish whiteberries. In thesummer the berriesare green; they arered in the spring andcan be yellow in earlyautumn.

Poison Ivyis a low vine that grows alongthe ground and often climbswalls, tree trunks, and bushes.It has bright green leaves that

have an oily toxin, whichcauses light tosevere allergicreactions. Thesymptoms canappear betweenone and threedays after havingtouched the plant.

Belladonna (DeadlyNightshade)has three alkaloids that are consideredpoisonous: hyoscine, scopolamine, and

atropine. These substances affect theautonomous nervous system, which

regulates breathing and cardiacrhythm. In medicine atropine in lowdosages decreases the intensity ofintestinal contractions.

10%OF VEGETABLE SPECIEShave alkaloids, compoundsformed with nitrogen.

Poison HemlockAlso known as Conium maculatum, this herbaceousplant belongs to the Umbelliferae family. It has ahollow, striated stem, with purple spots at its base.Though poisonous, it has been used to calm strongpains and headaches. Poison hemlock has acharacteristic offensive, urinelike odor. The activecomponent in hemlock is coniine, an alkaloid thathas neurotoxic effects.

BURNINGIntoxication produces adry mouth, dilatedpupils (mydriasis), andnausea.

1.

HEIGHTIt can grow to a height of6.5 feet (2 m).

HEIGHTIt can grow toa height of 10feet (3 m).

HEIGHTIt grows to aheight of 5feet (1.5 m).

PARALYSISThe legs weaken, themuscles become paralyzed,and respiratory failure andasphyxia take place.

2.DEATHThe subject remainsconscious until themoment of death.

3.

BelladonnaAtropa belladonna

Poison HemlockConium maculatum

A plant belonging to theUmbelliferae family that isconsidered toxic because ofits narcotic effects.However, it can also bemedically prescribed to treatdisorders such as epilepsy.

Poison IvyToxicodendronradicans


The colonization of America brought about the discovery of anextraordinary variety of plants that have been used as food for along time. An important example is the tomato, which is consumed

globally. The cultivation of the tomato has reached marked levels oftechnological complexity that help address problemsof infestation and adverse environmentalconditions, as well as make it possible togrow tomatoes without using soil.


Tomato Factories

FERTILIZERprovides the soil with nutrients. HIGH YIELD

The cultivatedfields are designedto make maximumuse of theavailable space.

LATE CROPTransgenic tomatoesmature more slowly thantomatoes that have notbeen modified.

GOOD NEIGHBORSRaising carrot andcabbage crops in thesame garden aids the development of tomatoes.

NETTLESdiscourage insectsthat destroytomatoes.

WaterAbsorptionArea

2 feet(0.7 m)

3 feet (1 m)

LEVEL A has nutrientsthat are essentialto the plant.

Planting

Harvesting

End of Winter

Beginning of Summer

Planting

Harvesting

Winter

Summer/Autumn

Traditional CultivationIn gardens, tomato plants are grown in accordance with theirannual growth cycle, using adequate soil and pest control.

SANDY LOAM SOILallows for the bestdevelopment oftomatoes.

THE AVERAGEWEIGHT OFTOMATOES APLANT CANPRODUCE INONE YEAR

Transgenic CropBiotechnology is used to create plants thatcan be cultivated in soils which, under normalconditions, would not be adequate (forinstance, soils with high salinity).

LEVEL A Highconcentrationof salts

LEVEL BThe clays retainwater that soaksinto the soil.

SALINE SOILSDue to a shortage inrain, the mineralsremain in Level A andincrease its salinity.

4 MULTIPLICATIONBacteria are cultivatedto replicate the alteredplasmids.

TRANSPLANTThe seedling canbe transplantedwhen it has threeor four real leaves.

6 to 8inches (15-20 cm)

IRRIGATIONEvery plant requiresmore than 0.5 gallon (2 l) of water every week as it grows.

HYDROPONICGREENHOUSESallow growers to controlthe light, water, nutrients,and temperature ofcultivation.

COLLECTING TANKThe water is collected, andits physical and chemicalproperties are analyzed.

PUMPPropels thewater towardthe irrigationtank

Drip-ControlFlowValve

IrrigatingPipes

The water flowsunder the forceof gravity.

Troughs

5.5pounds (2.5 kg)

plants peracre aredesired.

More

2

64-77° F(18-25° C)IS THE OPTIMALTEMPERATURE.

ORIGIN OF THE TOMATOIndigenous to Peru, it wasdomesticated in Mexico and CentralAmerica.

STAKEShelp the plantsto grow andremain upright.

Area of OriginMain Producers

SUBSTRATEInert materials, such as gravel orsand, work as substrates.

WATERWater haslong beenknown tobe vital toplants.

3 BACTERIAL DNAThe genes are insertedinto a bacterial plasmid.

1 DNAGenetic materialis chosen.

Sweet Potato WhiteflyBemisia tabaci

Green peach aphidMyzus persicae

Red Spider MiteTetranychusturkestani

LEVEL Ballows for goodwater drainage fromrain or irrigation.

65%Sand

25%Lime

10%Clay

30%Lime

40%Clay

MOST COMMON INFESTATIONS

30%Sand

Hydroponic CultivationWater and nutrients are sufficient to grow tomatoes. For this reason, itis possible to grow crops in inert substrates without any soil. Thistechnique is very useful for obtaining tomatoes in desert areas and formaking them available for harvest at any time of the year.

6 NEW FRUITSPlants are obtained thatproduce tomatoes withthe desired characteristic.

TRANSFERThe genes areinserted into theDNA of the plant.

GREENHOUSESeedlings growprotected fromfrosts.

TomatoSolanumlycopersicum

DRY CLIMATESThese climates are not appropriatefor planting tomatoes that are notmodified, but they can be used togrow modified crops.

5

WATERTANKcontainswater with an optimalamount ofnutrients.

GENESThe genes thathave the desiredcharacteristic areisolated.


Olive oil has been a part of people's diet since antiquity, and even today it is oneof the most popular oils because of its flavor and nutritious properties. Obtaininghigh-quality olive oil involves a chain of processes that begins at the tree and

ends with the packaging of the end product. The quality begins in the fields and dependson a combination of soil, climate, oil variety, and cultivation and harvesting techniques.The remaining operations in the extraction process (transportation, storage,manufacturing, and extraction of the oil) are responsible for maintaining that quality.


Olive Oil

After a good crop, olive trees usuallydo not produce well the following year.

AlternatingYears

Washing andClassificationThe fruits are carefully washedwith water and then classifiedaccording to their variety.

2

RefiningThe oil obtained is separated from the othersolid residues, impurities, and water. Sinceantiquity, this process has been carried out bydecantation, which requires letting the oil situndisturbed after it comes out of the press.Today it can also be carried out with verticalcentrifugal machines.

5

Bottlingis carried out in a plant, althoughsometimes it is done manually toensure product quality. Glass, alu-minum, and plastic containers areused. It cannot be stored where itwill be exposed to light, odors, orheat for extended periods.

7

PressingTraditionally, the paste thatincludes the entire olive isplaced on a system of stackeddiscs and then compressed bya hydraulic press.

4

StorageVirgin olive oil has nonfat components thathave to be preserved during storage andpackaging. It must be kept in a dark place at astable temperature.

6STONE WHEELHammer systemsare also used.

RESIDUEcan be used toobtain other oils.

STAINLESS STEEL HOPPERThe residues aredecanted at atemperature that is low, but not too low: oil crystallizes between32° and 36° F (0°-2° C).

THINGS TO AVOID

Contact with AirHeatExposure to Light

15 m

180 to 120plants

COLLECTIONHarvesting is done by hitting the treebranches, either byhand or mechanically,so that the fruits fallto the ground.

FILTERCentrifugalmachines arenow used.

LEAVES Opposed and lengthened,0.8 to 3 inches (2-8 cm)long, and with a pointedapical meristem

BOTTLEThis is how the oil is sentto the market.

LargeResidues

Residues

6m

7m

IS THE OPTIMUMDENSITY PERACRE (0.4 HA).

3 months IS THE LENGTH OF THE REFINING PERIOD.

TYPES OF OILThe classification of oildepends on the manufac-turing process and on theproperties of the product.The shorter the processing,the higher the quality.

OLIVE GROWTH STAGES(In the Southern Hemisphere)

Virgin Olive Oilis obtained bypressing,without anyrefining. It hasless than 2percent acidity.

Olive Oil can also beobtained bytreating theresidues withsolvents.

Refined Olive OilWhen this oil is refined,filtering soils are firstadded to purify it andthen decanted. Its acidcontent is lower thanthat of virgin olive oil.

A Flowersare distributedin clusters of10 to 40.

B Growth The pit or drupe(endocardium) hashardened; the fruitgrows.

September

October

November December

July

May

August

Green OliveThe appearanceof this colortells us thefruit is edible.

C

MaturingPurplespots beginto show.

DMature FruitThe oxidationprocess has givenit a black color.

E

Epicardium Endocardium

Mesocardium

Seed

IS THE QUANTITY OF OLIVES NEEDEDTO EXTRACT 0.5 GALLON (2 L) OF OIL.

22 pounds(10 kg)

OliveOleaeuropaea

MillingMachines break open thefruit and mix it to createa homogenous paste. Thismust be done on the daythe fruit is harvested.

3

PRESSThe press has ahydraulic mechanismthat compresses the disks.

DISKSThe olive paste is placed betweenthem to be pressed.

THE QUALITY OF THE OILThe oil that comes out of the firstpressing from good quality fruitsand with an acid level lower than0.8 percent is called extra virgin.After this pressing the other levelsof oil quality are obtained.

NEW PLANTINGSare propagated throughstaking, layering, orthe taking ofcuttings.

CultivationPlowed land, a moderate climate,an altitude of up to 2,300 feet(700 m) above sea level, and upto 15 inches (40 cm) of rain peryear sum up the conditionsneeded for the development ofolive plants.

HOMOGENIZINGThe oil from severalhoppers is mixed inthe final stage toobtain a uniformproduct.

COMPOSITION OF AN OLIVE

50%Water

19%Sugars

5.8% Cellulose1.6%Protein

1.6%Ashes

22%Oil

The basic process of manufacturing paper has not changed for2,000 years, although technology today allows us to manufacturepaper in quantities that are immeasurably greater than those of the

papyrus produced in antiquity. Paper is manufactured from a slurry thatcontains cellulose from tree trunks. Today the paper industry consumes 4billion tons of wood each year. Worldwide, one of the most commonlyused trees for paper manufacture is the eucalyptus because of its quickgrowth, its capacity to resprout trees from the stumps of young trees, itswood's quality, its consistency, and its yield. A disadvantage of eucalyptus isthat it requires more water for its growth than most other trees do.


From Tree to Paper

IS THE AMOUNT OFWOOD NEEDED TOPRODUCE ONE TONOF CELLULOSE.

4tons

gallons (300,000 l)OF WATER PER TON OF WOOD ISREQUIRED FOR THE PRODUCTION OFCARDBOARD, AND ABOUT 50,000GALLONS OF WATER PER TON (200,000L PER MT) OF WOOD ARE USED IN THEPRODUCTION OF PRINTING PAPER.

About

80,000


Manufactureof the PulpThe fibers are separated andsuspended in water so they can bepurified and bleached.

4Debarking, Washing,and SplinteringThe bark is separated from the trunk and eliminatedfrom the industrial process. The debarked trunk iswashed and cut into chips to facilitate handling.

3

Forming the PaperThe mixture of pulp, suspended inwater, passes into a machine withscreens that hold the fibers andallow the water to drain off. Sheetsof paper are the result.

6

DryingHeated rotating cylinders are used to press some of the remaining water from the paper. The final moisturecontent depends on the type of paper being made.

7

CultivationThe seedlings are obtainedin greenhouses and aretransplanted outdoors infurrows in the soil.

21,000 gallons(80,000 l)OF WATER ARE NEEDEDDAILY TO IRRIGATE 1ACRE (0.4 HA).

TRACTOROpens thefurrows in theearth

STAKEHelps keepthe plantupright

TRANSPLANTThe plant is placedin the center ofthe hole by hand.

FERTILIZEDIn furrowsperpendicular tothe incline ofterrain to preventsoil erosion bythe water

SOILClaylike andsiliceous, with apH between 5 and 7

SEEDLINGSare transplantedwithout using a hoein order not to bendthe plant.

CLEAR-CUTTINGMACHINECuts cleanly withoutdamaging the bark

TRANSPORTATIONBy trunks 8 feet (2.5 m) long

DEBARKERMachine withtoothed cylinders

DRYINGROLLERS

leave the watercontent of thepaper between 6and 9 percent.

WASHEREliminates sandand impurities

CHIPPINGMACHINEThe wood is cutinto chips.

GREENHOUSEKeeps seedlingsbetween 69° and80° F (21-27° C)

1

Initial

50 cubicfeet (15 cu m)IS THE AMOUNT OF WOOD PRODUCEDPER HECTARE.

4 billion TONS OF WOOD ISCONSUMED EVERY YEAR.

Clear-CuttingThe timing of the clear-cutting willdetermine the financial success ofthe forestry venture. Replantingtakes place right away.

2

10-13 yearsIS THE OPTIMAL AGE FOR CUTTING.

Moderate

Years

WoodProduction by Hectare (1 ha = 2.5 ac)

GROWTH RATEAfter approximately10 years the growthrate slows.

WEEDING ANDFUMIGATIONeliminate weeds andother plants. 15

0

50

250

300

05

10

Maximum

Rolling andConvertingThe dried paper is rolled ontoreels, and the rolls are cut.The paper can later be cutinto various sizes fordistribution and sale.

USES OF EUCALYPTUS GLOBULUS

LEAVESTheir resin isused in makingperfumes.

FLOWERIn Australia the flower ismost importantfor honeyproduction.

PhloemRings

16%is used in papermanufacturing.

BARKDisposed ofduring themanufacturingprocess

TRUNKIts components providethe fiber that will beused to obtain paper.

Cambium

MEDULLALarge cellswith soft-tissue walls

EucalyptusEucalyptus globulus

8

5 Bleaching andInclusion ofAdditivesBleaching is done with hydrogenperoxide, oxygen, sodiumhypochlorite, and other chemicals;glues, kaolin, talcum, plaster, andcolorants can be added.

WOOD

Bitter HerbsTheir action is focusedon the heart and thesmall intestine. Theylower fevers andsensations of heat, andthey redirect vitalenergy, or chi.

YINGarden angelica (Angelicaarchangelica), Italian cyprus(Cupressus sempervirens), commonhop (Humulus lupulus), rosemary(Rosmarinus officinalis)

YANGGreater plantain (Plantago major),dandelion (Taraxacum officinale),marjoram (Origanum majorana)

YINHeather (Calluna vulgaris),blessed milk thistle(Silybum marianum),ginseng (Panax ginseng)

YANGShepherd's purse(Capsella bursa-pastoris),red sandwort (Arenariarubra), rough bindweed(Smilax aspera)

YINGinger (Zingiber

officinale), peppermint(Mentha piperita), thyme

(Thymus vulgaris)

YANGCorn poppy (Papaver

rhoeas), Tasmanianbluegum (Eucalyptus

globulus), commonborage (Borago

officinalis)

YINChamomile (Matricaria chamomilla),

cinnamon (Cinnamomum zeylanicum),yellow gentian (Gentiana lutea), Minor

centaury (Centaurium umbellatum)

YANGLemon (Citrus limonum), common juniper

(Juniperus communis), lemon balm (Melissaofficinalis), cranberry (Vaccinium

myrtillus), olive (Olea europaea)

Sour Herbsbasically act on the liverand the gallbladder. They activate bilioussecretions.

Spicy Herbsinduce sweating, bloodcirculation, and chi, orvital energy. They are

generally used forsuperficial disorders.

Salty Herbsare refreshing; they softenhard spots, lubricate the

intestines, and promote theiremptying. They reduce

constipation, kidney stones,gout, etc.


Healing PlantsA

mong nature's many gifts are herbs, plants, and flowers that, sinceantiquity, have been used from generation to generation fortherapeutic purposes. Since humans began to care for their health,

these plants have been a key source of nutrition and healing. Likewise,modern medicine uses compounds derived from or obtained from herbs, roots, stems, leaves, flowers, and seeds.


Sweet Herbsare tonic and

nutritious. Theyharmonize with other

herbs, relieve pain, andstop the progression of

severe illnesses.

is the generatingprinciple of all things,according to Chinesephilosophy. It isrepresented with theyin and the yang,which together makeup the Taoist symbolknown as the “Taijitudiagram.” In order tomaintain good health,it is necessary tobalance yin and yang.

Chinese tradition adds metal to the elements ofthe Greek model (water, fire, air, and earth). Theinteraction among all these elements must bekept in equilibrium, with no single elementpredominating over the others. Should animbalance occur, an illness might appear.

TAI CHI ORTAI JI

THE THEORYOF THE FIVEELEMENTS

Chinese MedicineThe philosophy behindtraditional Chinese medicine

involves a qualitatively differentapproach from that of Westernmedicine. It is based on respect forthe interaction between the mind,the body, energy, and theenvironment. Its basic principlesinclude the five elements and theyin and yang. It is based on theconcept of chi, the vital energy inequilibrium in people's bodies.Chi regulates lost equilibrium.It is under the influence of the opposing forces of yin(negative energy) and yang (positive energy).Traditional Chinesemedicine includesherbal therapies,nutrition, physicalexercise, meditation,acupuncture, andhealing massages.

YINMotherwort (Leonurus cardiaca),Elecampane (Inula helenium), Englishlavender (Lavandula angustifolia)

YANGHawthorn (Crataegus oxyacantha),sour orange (Citrus aurantium),meadowsweet (Filipendula ulmaria)

approach, Ayurvedic medicine provides integratedtreatments that link physical care and meditationwith nutrition.

Ayurvedic Medicine in IndiaThe knowledge of life is the central principle ofayurvedic medicine. The representation of the

elements that form the Universe (fire, air, water, earth, andether) in three humors (vata, pitta, and kapha) indicate aperson's health and temperament. The energy centers, orchakras, of the body are stimulatedthrough the intake of herbs.

Contributions from the New WorldVarious plants were found to possess an impressive number ofsubstances that could be used for therapeutic purposes, as

antibiotics, contraceptives, anesthetics, and antipyretics (fever reducers),among others. One example is quinine, used in the treatment of malaria, which was originally obtained from the bark of the quinine tree (Chinchona species), a tree native to South America.

SHAMANSfulfill a central role inancient communities asrepositories of wisdom.Shamans seek to cureillnesses naturally, by meansof herbs, roots, and othervegetable substances.

ECHINACEA SP.The medicinal plant most used bynative North Americans. This plantstimulates the immune system.

INDUSTRYEchinacea is consumedaround the world as a

natural medicine.

Vata (wind) is associated with air and ether, pitta(anger) is associated with fire and water, and kapha(phlegm) is associated with earth and water. A holistic

THE THREE TYPES OF HUMORS

VATA(Wind)In excess, itinfluences theintestines, thecolon, the ears,the bones, thehips, and the skin.

DESCRIPTIONIt is associated with a melancholicpersonality, characteristic ofdreamy and erratic people.

METALWATER

PITTA(Anger) It affects theliver, gallbladder,stomach, eyes,skin, andpancreas.

KAPHA(Phlegm)In excess, it canaffect the throat,airways (upper andlower), and joints.

DESCRIPTIONIt represents a choleric personality—people who are decisive, with atendency to embrace new ideas.

DESCRIPTIONIt is associated with tranquility andserenity, typical characteristics ofpersons with a naturally sensitiveattitude.

EARTH

FIRE

YANGis consideredmale, bright,and hot.

YINis consideredfemale, dark,and cold.

Ginger

Fungi

For nearly a billion years theability of fungi to break downsubstances has been importantto life on Earth. These life-forms break down carbon

compounds and return carbon andother elements to the environment tobe used by other organisms. Theyinteract with roots, enabling them tobetter absorb water and mineral

nutrients. For many years fungi wereclassified within the plant kingdom.However, unlike plants, they cannotproduce their own food. Many areparasites. Some fungi are pathogens—

they can cause sickness in humans,animals, or plants.

ANOTHER WORLD 82-83

THE DIET OF FUNGI 84-85

POISON IN THE KINGDOM 86-87

PATHOGENS 88-89

DESTROYING TO BUILD 90-91

AMANITA MUSCARIAThe quintessential toadstool hasunpleasant psychoactive effects.Depending on the dose, they rangefrom dizziness, muscle cramps, andvomiting to amnesia.

Another World

VARIETYThere are greatanatomical differencesamong theChytridiomycetes. Inthe same reproductivephase they canproduce haploid anddiploid spores.

CAPPEDMUSHROOMSWith itsrecognizable shape,the mushroom's capprotects thebasidia, whichproduce spores.

Fungi can develop in all sorts ofenvironments, especially damp and

poorly lit places, up to elevations of 13,000feet (4,000 m). They are divided into four large phyla, in addition to a group of fungi

called “imperfect” because they generallydo not reproduce sexually. At present,15,000 species of fungi fall into thiscategory. DNA analysis has recentlyreclassified them as Deuteromycetes.

Fungi: A Peculiar Kingdom

82 FUNGI

39°to140°F (4°-60° C)THE TEMPERATURE RANGE INWHICH MOST FUNGI CAN LIVEIN HUMID CLIMATES

80,857DIFFERENT SPECIESHAVE BEEN IDENTIFIED IN THEFUNGI KINGDOM. THERE AREBELIEVED TO BE APPROXIMATELY1,500,000 SPECIES.

Chytridiomycotaare the only fungi that, at some point intheir lives, have mobile cells—male andfemale gametes, which they release intowater in order to reproduce. They live inwater or on land, feeding on deadmaterial or living as parasites on otherliving organisms. Their cell walls aremade of chitin.

Deuteromycotaare also called “imperfect fungi” because they arenot known to have a form of sexual reproduction.Many live as parasites on plants, animals, orhumans, causing ringworm or mycosis on theskin. OthersΩsuch as Penicillium, which producespenicillin, and CyclosporaΩhave great medicinaland commercial value.

Ascomycotais the phylum with the most speciesin the Fungi kingdom. It includesyeasts and powdery mildews, manycommon black and yellow-greenmolds, morels, and truffles. Itshyphae are partitioned into sections.Their asexual spores (conidia) arevery small and are formed at theends of special hyphae.

0.1 inch(3 mm)

Slime MoldPhysarum polycephalum

Pathogenic MoldAspergillus niger

ErgotClavicepspurpurea

Black Bread MoldRhizopusnigricans

Chanterelle MushroomCantharellus cibarius

Spores

FruitingBodies

Conidiophores

Hyphae

Mycelium

WhiteMycelium

OF UNKNOWN SEXIn Deuteromycetes, conidia are tiny sporesthat function asexually. They are contained instructures called conidiophores.

4.5 inches(120 mm)

0.01 inch(0.3 mm)

0.6 inch(15 mm)

0.01 inch(0.3 mm)

Zygomycotais a phylum of land-growingfungi that reproduce sexuallywith zygosporangia, diploid cellsthat do not break their cell wallsuntil conditions are right forgerminating. They also reproduceasexually. Most zygomycetes livein the soil and feed on plants ordead animal matter. Some live asparasites on plants, insects, orsmall land animals.

MANY LITTLEPOUCHESIts spores areformed when twogametes ofopposite sexesfuse. It can alsoreproduceasexually, whenthe sporangiumbreaks andreleases spores.

EXPLOSIVEAt maturity the asciburst. The explosionreleases their sexualspores (ascospores)into the air.

BasidiomycotaThis phylum, which includes mushrooms, is the mostfamiliar of the fungi. The mushroom's reproductiveorgan is its cap. Its branches grow underground orinto some other organic substrate.

Ascus withAscospores

For many years fungi were classified within the plant kingdom. However, unlike plants, they areheterotrophic—unable to produce their own food.

Some fungi live independently, whereas others areparasitic. Like animals, they use glycogen for storingreserves of energy, and their cell walls are made of chitin,the substance from which insects' outer shells are made.

Spores

Thallus

Basidia

Mycelium

Mycelium

Sporangiophore

Sporangium

Ascocarp

Hypha

Ascus

PLANTS, ALGAE, AND FUNGI 8584 FUNGI

The Diet of FungiF

ungi do not ingest their food like animals. On the contrary, theyabsorb it after breaking it down into small molecules. Most of themfeed on dead organic material. Other fungi are parasites,

which feed on living hosts, or predators, which live off theprey they trap. Many others establish relationships ofmutual benefit with algae, bacteria, or plants andreceive organic compounds from them.

PARASITESFungi such as Ceratocystisulmi and Agrocybe aegerita(shaded areas on the leaf)live at the expense of otherplants, which they can evenkill. Others live parasiticallyoff animals.

SAPROBESThere is no organicmaterial that cannot bebroken down by this typeof fungus. They actuallylive on the dead parts ofother plants, so they causeno harm to the host.

SYMBIOTICWhile feeding off the plant,they help it to obtain waterand mineral salts moreeasily from the soil. Eachspecies has its owncharacteristics.

The organic or inorganic substances that fungifeed on are absorbed directly from the

environment. Fungi first secrete digestive enzymes ontothe food source. This causes a chemical transformationthat results in simpler, more easily assimilatedcompounds. Basidiomycetes are classified according totheir diet. For example, they colonize different partsof a tree depending on the nutrients they require.

Chemical Transformation

MYCELIUMWhen a mushroom spore finds the right medium, itbegins to generate a network of hyphae, branchingfilaments that extend into the surrounding medium. Thismass of hyphae is called a mycelium. A mushroom formswhen threads of the mycelium are compacted and growupward to create a fruiting body.

FRUITING BODYThe basidiocarp,or mushroom cap,generates newspores.

VEGETATIVEMYCELIUMIt is made ofbranches ofthreadlike hyphaethat growunderground.

Fungi of the genus Amanita, including thepoisonous A. muscaria shown here, have the well-known mushroom shape with a mushroom cap.

Hyphae

Spore-producingstructures

GrowthAt birth the fruiting body of thespecies Amanita muscaria looks like awhite egg. It grows and opens slowlyas the mushroom's body unfolds. As itgrows the cap first appearscompletely closed. During the nextseveral days it opens like an umbrellaand acquires its color.

CUTICLE

The skin, or membrane, that covers the cap,or pileus, is called the cuticle. It can have avariety of colors and textures, such asvelvety, hairy, scaly, threadlike, fibrous,fuzzy, smooth, dry, or slimy.

Fungi can break down an impressive variety ofsubstances. For example, a number of species can

digest petroleum, and others can digest plastic. Fungialso provided the first known antibiotic, penicillin. Theyare now a basic source of many useful medicalcompounds. Scientists are studying the possibility ofusing petroleum-digesting fungi to clean up oil spills andother chemical disasters.

Did You Know? HALLUCINOGENICMUSHROOMPsilocybin aztecorum

CAPBesides being easy to spot,the cap is the fertile partof basidiomycetes; itcontains spores.

LIFE CYCLE OF A FUNGUSFungi produce spores duringsexual or asexualreproduction. Spores serve totransport the fungus to newplaces, and some help thefungus to survive adverseconditions.

HYMENIUMIt is located on the underside of the cap. It contains very fine tissues that produce spores. Itsstructure can consist of tubes,wrinkles, hairlike projections, oreven needles.

BASIDIAare fine structures thatcontain groups of fourcells, which are able toreproduce.

Development of thefruit-bearing body

Release ofspores

Strobilurus esculentus

lives on the cones ofvarious pine trees.

GILLSare the structures thatproduce spores. Theirshape varies accordingto the species.

Basidiospore

Basidium

Detailof aGill

Spore formation byfertilizationHyphae

formation

STEMCylindrical inshape, it holds upthe cap andreveals importantinformation foridentifying thespecies.

RINGAlso known asthe veil, itprotects part ofthe hymenium inyoung fungi.

VOLVAThe volva is made of theremains of theearly rings thathave fallen off. Itdiffers fromspecies to species.


Poison in the KingdomA

poisonous fungus is one that, when ingested, causes toxic effects. In termsof its effects on the eater, the toxicity can vary according to the species andto the amount ingested. At times poisoning is not caused by eating fungi but

by eating foods, such as cereal products, that have been contaminated by a fungus.Rye, and to a lesser extent oats, barley, and wheat, can host toxic fungi thatproduce dangerous mycotoxins. These mycotoxins can cause hallucinations,convulsions, and very severe damage in the tissues of human organs.

Pretty ButDeadlyThis mushroom is toxic to the liver. Itgrows from spring to fall, often insandy, acidic soil in woodlands andmountainous regions. Its cap is whiteand 2 to 5 inches (5-12 cm) in diameter.Its stem and gills are also white, andthe gills may appear detached from thestem. The base of the stem has acuplike volva, but it may be buried orotherwise not visible.

Insecticide The fly agaric's name is thought to come from its natural fly-killingproperties. Its cap is typically red and 6 to 8 inches (15-20 cm) indiameter. It may be covered with white or yellow warts, but they areabsent in some varieties. The stem is thicker at the base, which lookscottony. It also has a large white ring that looks like a skirt. It grows insummer and fall in coniferous and deciduous forests. If eaten, it causes gastrointestinal and psychotropic symptoms.

DESTROYINGANGEL Amanita virosa

Eating the fruiting bodies of some species can bevery dangerous if it is not clearly known which

are edible and which are poisonous. There is no suremethod for determining the difference. However, it isknown for certain that some speciesΩsuch as certainspecies of the genera Amanita, Macrolepiota, andBoletusΩare poisonous.

Poisonous Mushrooms

FruitThe perithecium is a type offruiting, or reproductive, bodyin ascomycetes. It is a type ofclosed ascocarp with a poreat the top. The asci are insidethe perithecium.

2. SporesThe asci are sac-shaped cellsthat contain spores calledascospores. In general, theygrow in groups of eight andare light enough to bescattered into the air.

3.

ParasitesAscospores of sexual originor asexual conidia developas parasites in the ovary ofthe rye flower. They causethe death of its tissues andform sclerotia. In somelanguages ergot's name isrelated to the word for“horn” because of sclerotia'shornlike shape.

4.

ReleaseWithin the enclosing structuresa stroma, or compact somaticbody, is formed. Inside itreproductive growths develop,which contain a large numberof perithecia.

1.

Ergot (Claviceps purpurea) is aparasite of rye and produces

alkaloid mycotoxins—ergocristine,ergometrine, ergotamine, andergocryptine. When barley with ergot isprocessed for use in food, themycotoxins can be absorbed wheneaten. All these toxic substances can actdirectly on nerve receptors and causethe constriction of blood vessels.

Attack on Rye

In Europe during the Middle Ages wheat breadwas a costly food, not part of the common diet.

Most people ate bread and drank beer prepared fromrye. This made them susceptible to ingestingmycotoxins from Claviceps purpurea. Thus, the largestnumber of cases of ergotism occurred during this time.Today preventative controls in the production of breadand related products from rye and other cereals havegreatly reduced instances of ergotism.

RYE BREAD

WHISKEY

FLOUR

Ergotism, or St. Anthony's Fire, is acondition caused by eating products

such as rye bread that have beencontaminated with alkaloids produced byClaviceps purpurea fungi, or ergot. Thealkaloids typically affect the nervous systemand reduce blood circulation in theextremities, which produces the burningsensation in the limbs that is one of thecondition's notable symptoms.

EXTREMITIESErgotamine alkaloidscause the constrictionof blood vessels,leading to gangrene.

NERVOUS SYSTEMLethargy, drowsiness, andmore severe conditions, suchas convulsions, hallucinations,and blindness, are symptomscaused by the effects of ergoton the nervous system.

ErgotismINGESTIONThe main meansof intake of themycotoxins isthrough productsmanufacturedwith flour.

Derived from Rye

ERGOTISM (ST.ANTHONY'S FIRE)

FLY AGARICAmanita muscaria

ERGOT Claviceps purpurea


Pathogens

88 FUNGI

Fungi that are able to cause illnesses in people, animals, or plantsare called pathogens. The nocive, or toxic, substances that theseorganisms produce have negative effects on people and cause

significant damage to agriculture. One reason these pathogens are sodangerous is their high tolerance to great variations in temperature,humidity, and pH. Aspergillus is a genus of fungi whose memberscreate substances that can be highly toxic.

ALLERGENICS Aspergillus flavus

This species is associated withallergic reactions in people with agenetic predisposition to thisallergy. They also cause thecontamination of seeds, such aspeanuts. They produce secondarymetabolites, called micotoxins, thatare very toxic. SAPROBIA Aspergillus sp.

In addition to thepathogen species, there aresome species of Aspergillusthat decompose theorganic matter of deadinsects, thus incorporatingnutrients into the soil.

AspergillumAspergillus are “imperfect” fungi, ordeuteromycetes, that are characterizedby having reproductive structures calledconidial heads. The head is composed of avesicle that is surrounded by a crown ofphialides shaped like a bottle, at the endof which spore chains form.

THE NUMBER OFASPERGILLUS SPECIES. THEYHAVE BEEN CLASSIFIED INTO18 GROUPS. MOST OF THESESPECIES ARE ASSOCIATEDWITH HUMAN ILLNESSES,SUCH AS ASPERGILLOSIS.

900

SPECIES ARE ASSOCIATEDWITH HUMAN ILLNESSES.ASPERGILLUS FUMIGATUS,A. FLAVUS, A. NIGER, AND A.TERREUS ARE EXAMPLES.

12

BREAD MOLD Aspergillus niger

The fruiting body is yellowishwhite, but it will turn black whenthe conidia mature. Itsconidiophores are large and havephialides that cover all its conidialhead vesicle. They can be found inmold-covered food.

OPPORTUNISTICAspergillus fumigatus

This pathogen canaffect people whoseimmune systems areweakened. It cancause serious invasivediseases.

CONIDIAare so small thatthey spread throughthe air without anydifficulty.

CONIDIOPHOREThe part of themycellium of thefruiting, orreproductive, bodyin which asexualspores, or conidia,are formed

PHIALIDESare cells fromwhich conidia areformed.

CONIDIAL HEADHas a greenishmycellium and shortand abundantconidiophores.

CONIDIA CHAINConidia are asexualspores that form atthe ends of thehyphae. In this casethey group togetherin chains.

CELL MEMBRANEThe cell membranecontrols what enters orexits the cell. It acts asa selective filter.

Yeast from the genus Sacchromyces cerevisiae can reproduce bothasexually and sexually. If the concentration of oxygen is adequate, the

yeasts will reproduce sexually, but if oxygen levels are drastically reduced,then gemation will take place instead. Gemation is a type of asexualproliferation that produces child cells that split off from the mother cell.Starting with barley grain, this process produces water, ethyl alcohol, and alarge quantity of CO2, the gas that forms the bubbles typically found in beer.

NUCLEUSIt coordinates all thecell's activities. Itsduplication is vital inmaking each child cellthe same as itsprogenitor cell.

MITOCHONDRIAThese subcellularstructures become veryactive when the cell isin an environment richin oxygen.

VACUOLEThis organelle contains waterand minerals that are used inthe cell's metabolism. Theconcentration of thesenutrients helps regulate theactivity of the cell.

ENZYMEPRODUCTIONInternal membranesystems produce theenzymes that regulate theproduction of alcohol andcarbon dioxide in the cells.

GEMATIONBuds, or gems, which willbecome independent in anew cell, are formed indifferent parts of a yeast.

RELEASE OF THEASCOSPORESThe opening of theascus releases thespores, which thenreproduce bymitosis.

UNION OF THEASCOSPORESThe haploid cellsfuse and form anew diploid cell.

GEMATIONUnder the right conditionsthe diploid cells begin toreproduce asexually.

MULTIPLICATIONA large number ofcells are producedin this stage.

MEIOSISA diploid cell formsfour haploid cells.

SPORESA sac called an ascus isformed that containsascospores of yeast.

1

2

3

4

5

6

FermentationUnder anaerobic conditions yeasts canobtain energy and produce alcohol. Bymeans of the alcoholic fermentationprocess they obtain energy from pyruvicacid, a product of the breakdown ofglucose by glucolysis. In this process CO2

is also produced and accumulated, as isethyl alcohol. The carbon dioxide will bepresent in the final product: the beer.

YeastSaccharomycescerevisiae

12%THE MAXIMUM PERCENTAGE OF ALCOHOL THAT YEASTWILL TOLERATE

CycleGROW AND MULTIPLYAs long as they have adequatenutrients, yeasts will continuouslyrepeat their reproductive life cycle.

Many products are made with yeasts, and one of the mostimportant is bread. In the case of bread, yeasts feed off

the carbohydrates present in flour. Bread products, unlikealcoholic beverages, need to have oxygen available for the yeastto grow. The fungi release carbon dioxide as they quickly consumethe nutrients. The bubbles of carbon dioxide make the doughexpand, causing the bread to rise.

Homemade Bread

YeastSaccharomycesellipsoideus


Destroying to BuildY

easts, like other fungi, decompose organic material. This capacity canbe beneficial, and, in fact, human beings have developed yeast productsfor home and industrial use, such as bread, baked goods, and alcoholic

beverages, that attest to its usefulness. Beer manufacturing can beunderstood by analyzing how yeasts feed and reproduce and learning what they require in order to be productive.

Precious Gems

WINE YEASTYeast is also used toproduce wine. In wineproduction, however, theCO2 that is produced iseliminated.

92 GLOSSARY PLANTS, ALGAE, AND FUNGI 93

Glossary

Adventitious RootRoot that appears in unusual places, such ason the stem

AlgaeOrganisms of the Protist kingdom, at one timeconsidered plants, but without roots, stems, orleaves. They live in water or in humid areas.They can be pluricellular or unicellular.

AlleleGene variant that encodes a trait. One diploidcell contains one allele from each parent foreach characteristic.

AnaerobicReaction, or series of reactions, that does notrequire oxygen

AnalogySimilarity produced in similar environmentsthrough the adaptation of species that do nothave a common ancestor

AngiospermsFrom the Greek angion (recipient) and sperm(seed). Plants with flowers whose seeds arecontained in structures that develop into fruits.

AntherStructure of the stamen composed of twolocules and four pollen sacs

Asexual ReproductionProcess through which a single progenitorgenerates descendants identical to itself

ATPAdenosine triphosphate. Molecule produced bythe mitochondria, which functions as the mainsource of energy for cells.

BerrySimple fleshy fruit formed by one or morecarpels

BiomeEcosystem that occupies a large area and ischaracterized by specific types of vegetation

BryophytesGroup of small flowerless plants that comprisethe hepaticae, anthocerotae, and mosses

BulbModified structure of the stem in which starchaccumulates in thickened leaves

CambiumInterior part of the root and the stem of aplant that forms xylem on one side and phloemon the other. It makes stems grow thicker.

CarpelFemale part that bears the ovules of a flower.The grouping of carpels forms the gynoecium.

CellSmallest vital unit of an organism. Plant cellshave a wall that is more or less rigid.

Cellular MembraneFlexible cover of all living cells. It containscytoplasm and regulates the exchange ofwater and gases with the exterior.

Cellular RespirationAerobic processes that extract energy fromfood, including glycolysis, oxidativephosphorylation, and the Krebs cycle.Eukaryote cells carry out these processes inthe cytoplasm and the mitochondria.

DicotyledonFlowering plant whose seed has twocotyledons

DiploidCell with two complete sets of chromosomes

DNADeoxyribonucleic acid. Double helix moleculewith codified genetic information.

DrupeSimple fleshy fruit that develops fromhypogynous flowers—flowers in which theovary lies above the point where the otherflower parts are attached. It has one seed inits interior. Examples include the olive, peach,and almond.

EcosystemGrouping of the organisms of a community andthe nonbiological components associated withtheir environment

EmbryoProduct of an egg cell fertilized by a spermcell; it can develop until it constitutes an adultorganism.

EndodermisLayer of specialized cells, composed of thickercells; in young roots it is found between thebark and the vascular tissues.

Endoplasmic ReticulumNetwork of membranes connected through thecytoplasm that serves as a site of synthesisand assembly for the cell to form its proteins

EnzymeProtein that helps to regulate the chemicalprocesses in a cell

EpidermisThe most external cellular layers of stems andleaves

EpiphytePlant that grows and supports itself on thesurface of another plant but does not takewater or nutrients from it

FamilyTaxonomic category, inferior to order, thatgroups the genera

FertilizationFusion of the special reproductive cells(contained in the pollen and in the ovules) inorder to give rise to a new plant

FilamentStructure, in the form of a thread, that formsthe support of a flower's stamen

FruitOvary or group of ovaries of a flower,transformed and mature. It contains the seeds.

GametangiumUnicellular or multicellular structure fromwhich the gametes, or reproductive sexualcells, originate

GeneUnit of information of a chromosome.Sequence of nucleotides in the DNA moleculethat carries out a specific function.

Genetic DriftPhenomenon produced in small populationsthat demonstrates that the frequency of allelescan vary by chance or throughout generations

GerminationProcess in which a plant begins to grow froma seed or a spore

GymnospermPlants with seeds that are not sealed in anovary. Examples are conifers (pine, fir, larch,cypress).

GynoeciumGrouping of carpels of a flower that make upthe female sexual organ of angiosperms

HaploidFrom the Greek haplous, singular: cell with oneset of chromosomes, unlike diploids. It ischaracteristic of the gametes, thegametophytes, and some mushrooms.

HaustoriaVessels with which some parasitic plantspenetrate other species in order to feedthemselves from substances photosynthesizedby the host

HostPlant from which another organism (parasite)obtains food or shelter

HyphaeInterwoven filaments that form the myceliumof fungi

InflorescenceGroupings of flowers in a specific form on apeduncle

KingdomTaxonomic group superior to a phylum andinferior to a domain, such as the kingdomPlantae

CelluloseFibrous carbohydrate that a plant produces aspart of its structural material. Main componentof the cell wall.

ChitinPolysaccharide that contains nitrogen. It ispresent in the cell walls of mushrooms.

ChlorophyllPigment contained in the chloroplasts of plantcells. It captures the energy of light duringphotosynthesis.

ChloroplastMicroscopic sac, located on the inside of green-plant cells, where the chemical processes ofphotosynthesis take place

CiliumShort external appendage that propels a celland is composed of microtubules

ClassTaxonomic group superior to order and inferiorto phylum. For example, the Charophyceaeclass includes green algae related to higherplants.

CotyledonFirst leaf of flowering plants, found on theinside of the seed. Some store food and remainburied while the plant germinates.

CytoplasmCompartment of the cells of eukaryotes,marked by the cellular membrane and themembranes of the organelles of the cell

DeciduousDescribes a plant that loses all its leaves inspecific seasons of the year

94 GLOSSARY PLANTS, ALGAE, AND FUNGI 95

LegumeSimple fruit of some species that come fromone carpel divided in two. Examples aregarbanzos and peas.

LichenThe symbiotic union of a fungus and an alga;the food is synthesized by the algae and usedby the fungus, which offers the alga a moistand protected habitat in which to live.

LigninA substance related to cellulose that helpsform the woody parts of plants

LigulaPetal developed on the border of the head ofcertain composite flowers. Its color may beblue or yellow, or more commonly, white, as inthe case of daisies.

MacronutrientEssential chemical element that a plant needsin relatively large quantities and that isinvolved in its vital processes. Examples arenitrogen and phosphorus.

MedullaBasic tissue formed inside the vascular tissue

MeiosisType of cellular division in which twosuccessive divisions of the diploid nucleus of acell give rise to four haploid nuclei. As a result,gametes or spores are produced.

MeristemRegion of tissue consisting of cells thatproduce other cells through cellular division

MitochondriaOrganelle delimited by a double membrane. Init, the final stage of aerobic respiration iscarried out, in which ATP is obtained from thedecomposition of sugars.

MitosisNuclear division that forms two descendantnuclei identical to the progenitor

Molecular ClockMarker used to calculate the evolutionarydistance between two species. It is evaluatedby comparing the gradual accumulation ofdifferences in amino acids among the proteinsof each species.

MonocotyledonsFlowering plants with only one cotyledon.Examples are the onion, orchid, and palm.

MyceliumInterwoven mass of hyphae of a fungus

NectarSweet liquid, produced by flowers and someleaves, that attracts insects and birds, whichserve as pollinating agents

NodeAxillary bud, the part of the stem of a plantwhere one or more leaves appear

NucellusStructure located inside plants with seeds,where the embryonic sac is developed

Nucleic AcidA molecule that carries genetic informationabout the cell

NucleusThe part of the cell that contains the DNA,which carries the genetic material

OsmosisThe movement of a liquid through a selectivelypermeable membrane

PolymerMacromolecule formed from repeatedstructural units called monomers

PolypeptidePolymer of amino acids; examples are proteins.

ProteinMacromolecule composed of one or morechains of amino acids. They define the physicalcharacteristics of an organism and regulate itschemical reactions when they act as enzymes.

ProtoplastPlant cell without a cell wall

RhizoidsCellular formation or filament in the form of athin and branching tube that attaches mossesto the soil

RhizomeHorizontal subterranean stem

RibosomeOrganelle located in the cytoplasm that directsthe formation of proteins on the basis ofinformation given by the nucleic acids

RootOrgan that fixes a plant to the soil and absorbswater and minerals from it

SapWatery liquid that contains the products ofphotosynthesis and is transported by thephloem

SeedStructure consisting of the embryo of a plant,a reserve of food called the endosperm, and aprotective cover called the testa

SeedlingFirst sprouting of the embryo of a seed, formedby a short stem and a pair of young leaves

SepalModified leaf that forms the outer covering ofa flower that protects the bud before it opens

Sexual ReproductionReproduction based on the fertilization of afemale cell by a male cell; it producesdescendants different from both progenitors.

SoriSet of sporangia found on the underside offern leaves

SporeReproductive structure formed by one cell,capable of originating a new organism withoutfusing with another cell

SporangiaStructure in which spores are formed

StamenElement of the male reproductive apparatus ofa flower that carries pollen. It is formed by afilament that supports two pollen sacs on itsupper part.

StemPart of a plant that holds up the leaves or thereproductive structures

StigmaUpper part of the female reproductiveapparatus of a flower. The receptor of pollen,it connects with the ovary.

Storage organPart of a plant that consumes sugars orfunctions to store sugars. Examples are stems,roots, and fruit.

ThallusPlantlike body of brown seaweed. Also thelong, rigid part that holds up the reproductivestructures of some fungi.

ThylakoidSmall, flat sac that makes up part of theinternal membrane of a chloroplast. Site wheresolar energy is transformed into chemicalenergy as part of the process ofphotosynthesis.

TissueGroup of identical cells with the same function

TuberModified, thickened underground stem wherethe plant accumulates reserves of foodsubstances

VascularDescribes plants with a complex structure andhighly organized cells for transporting waterand nutrients to all parts of the plant

XerophytePlant that grows in deserts and other dryenvironments

XylemPart of a plant's vascular system. It transportswater and minerals from the roots to the restof the plant.

OvaryThe part of a flower consisting of one or morecarpels and containing the ovules. Fertilized, itwill form all or part of the fruit.

OvuleThe part of the ovary in flowering plants thatcontains the female sexual cells. Afterfertilization it transforms into seed.

ParasiteAn organism that lives at the expense ofanother, from which it obtains its nutrients

PetalModified leaves that form the corolla

PhloemVessels that conduct the sap throughout theentire plant

PhotorespirationProcess through which some plants close theirstomas in order to avoid dehydration

PhotosynthesisProcess through which the energy of light isused to produce carbohydrates from carbondioxide and water

PhytoplanktonGroup of free-living microscopic aquaticorganisms with the capacity to carry outphotosynthesis

PollenFine powder of plants with seeds whose grainscontain the male sexual cells

PollinationPassage of pollen from the male organ of aflower to the female organ of the same floweror another

96 INDEX PLANTS, ALGAE, AND FUNGI 97

Index

AAcer pseudoplatanus L.: See sycamore mapleAcer sp.: See mapleacorn, 15aerenchyma, 10agar, 26Agaricus bisporus: See white mushroom aggregate fruit, 55air pollution, moss, 30alcohol, 90-91algae, 18-27

classification, 8colors, 8lichens, 28-29photosynthesis, 16

algin, 26allergenic fungus, 88amphibious plant, 11angiosperm

classification, 9known species, 51wood, 45See also flower; inflorescence

anthesis, 38aphid, green peach (Myzus persicae),

tomatoes, 72apple, 54apical bud, 47aquatic plant, 10-11

carnivorous plants, 61stems, 42

Araucaria, 56arrowhead (Sagittaria sagittifolia), 11artichoke thistle (Cynara cardunculus), 42-43Ascomycota (Ascomycetes), 83Aspergillus flavus, 88Aspergillus Níger: See bread moldAtropa belladonna: See belladonnaayurvedic medicine, 78

Bbark

tree anatomy, 15wood, 44-45

Basidiomycota (Basidiomycetes), 83bee

orchid, 52-53pollination, 38, 52-53

beech (Fagus sp.), 13beer manufacturing, yeast, 90, 91belladonna (deadly nightshade, Atropa

belladonna), 71Bemisia tabaco: See sweet potato whiteflyberry, 54biotechnology, tomatoes, 73black bread mold (Rhizopus nigricans), 83blackberry, 55bladderwort (Utricularia vulgaris), 11, 61bract, buds, 47branching

buds, 46inflorescences, 66 root systems, 40

bread, 90bread mold (Aspergillus niger), 88bristlecone pine (Pinus longaeva), 45Bromeliad, 62brown seaweed, 20bryophyte, 8, 31bud, 46-47

tree, 14yeast, 91

Ccabbage: See red cabbagecactus, 68-69

species number, 6Calvin cycle, 17carbon, 17carbon dioxide, 16

concaulescence, 46cone, 9, 56, 57conifer, 56-57

classification, 9needles (leaves), 49wood, 45

Conium maculatum: See poison hemlockcorymb, 66cultivation

olives, 74-75tomatoes, 72-73tress, 76

cycad, 9Cynara cardunculus: See artichoke thistle

Ddaisy, 67deadly nightshade (belladonna, Atropa

belladonna), 71dehiscent fruit, 55dendrochronology, 44destroying angel mushroom, 87Deuteromycota (Deuteromycetes), 82Devonian Period, 45diatomaceous algae, 18-19dicotyledon plant

root systems, 40flowers, 50wood, 45

dioecious plant, 9Dionaea muscipula: See Venus flytrapdodder, 65Drosera capensis, 61drupe, 54dry fruit, 55

Eechinacea, 78Echinocactus grusonii: See golden barrel cactus

ecosystem, aquatic plants, 10eelgrass, 11energy conversion, 48environment

Fungi, 80-81leaves, 49

epiphyte, 62-63adaptions, 13parasitic, 64-65

ergot (Claviceps purpurea), 83, 86ergotism (St. Anthony's fire), 86Eryngium giganteum: See giant sea hollyEucalyptus globulus (Tasmanian bluegum)

uses, 76yin and yang, 79

European mistletoe, 64evergreen, 56evolution, 12-13

FFagus sp.: See Beechfermentation, 90fern, 32-33

classification, 8Dryopteris filix-mas, 12epiphytes, 62

Ficus nymphaeifolia: See strangler figfield poppy (Papaver rhoeas)

first twenty days, 37reproduction, 38-39

fig, 55flower, 50-51

anthesis, 38clustered (inflorescences), 66-67development, 37Eucalyptus globulus, 76green revolution, 5modified leaves, 67multiple fruit, 55orchids, 9pollination, 38, 52-53reproduction, 38-39

trees, 14whorls, 38

fly, 60fly agaric mushroom, 87flytrap, 61

venus flytrap, 58-59food, 5fruit, 54-55

acorn, 15cactus, 69epiphytes, 63field-poppy seeds, 39

Funaria higrometrica, 31fungus (Fungi), 80-91

classification, 8, 9lichens, 28-29species number, 12

Ggamete

algae, 22-23ferns, 32-33flowers, 38-39mosses, 30-31

geotropismroot development, 40seed and root, 36

germination seeds, 36-37spores, 30

giant sea holly (Eryngium giganteum), 46giant sequoia (Sequoiadendron giganteum)

height 13trunk, 6-7wood, 45

ginkgo, 8, 9gnetophyta, 9golden barrel cactus (Echinocactus grusonii),

69grass, 13gravitotropism: See geotropismgreen algae, 8

Carboniferous Period, 5carnivorous plant, 60-61

bladderwort, 11venus flytrap, 58-59

carrageenan, 26Castanea sp.: See chestnutcastor bean (Ricinus communis), 71catkin, 66cattail (Typha sp.), 11Cattleya trianae, 9cedar (Taxodiaceae), 56cell

epiphyte leaves, 63photosynthesis, 16-17root systems, 40yeasts, 90-91

cellulose, 16cereal grain, 9

rice, 4wheat, 9

chanterelle mushroom (Cantharellus cibarius), 83

chestnut (Castanea sp.), 13China

algae industry, 26-27medicine, 79

chlorophyll, 8leaf pigment, 16plants lacking, 65tree, 15

chlorophyte, 21chloroplast, 16, 17Chytridiomycota (Chytridiomycetes), 82Citus ladanifer: See gum rockroseclary sage (Salvia sclarea), 46classification, 8-9

flowering plants, 50Fungi, 82-83

Claviceps purpurea: See ergotclimate

lichens, 28trees, 14

compound leaf, 48compound raceme, 66compound umbel, 66

98 INDEX PLANTS, ALGAE, AND FUNGI 99

greenhousehydroponic cultivation, 73tomato cultivation, 72tree cultivation, 76

green peach aphid (Myzus persicae), tomatoes, 72

growth ring, trees, 15, 44gum rockrose (Citus ladanifer), 46gymnosperm

classification, 9, conifers, 56wood, 45See also conifer

Hhead (flower type), 66heartwood, 45heliophilic plant, 10hemlock, 70hormone (plant), 36hornwort, 10horsetail rush, 8hydroponic cultivation, tomatoes, 73

I-KIndia, ayurvedic medicine, 78inflorescence (clustered flowers), 66-67insect

carnivorous plants, 58-61clustered flower fertilization, 67

Japan, algae industry, 26Juglans sp.: See walnutkingdom, 8-9, 82knotweed (Polygonum sp.), 11

Llaburnum, wood, 44Lachenalia, 11lateral bud, 47leaf, 48-49

cactus, 69conifer, 56epiphytes, 62, 63Eucalyptus globulus, 76first true, 37floating leaves, 10green color, 16growth of new, 46-47inflorescences, 66-67oaks, 15olives, 74photosynthesis, 16-17

Leonurus cardiaca: See motherwortlichen, 28-29

environment, 49light, 16, 24, 48linden (Tilia sp.), 13

M-Nmaple (Acer sp.)

leaves, 48-49plant adaptations, 13sycamores, 46-47

marine algae, 24-25medicinal algae, 27medicinal plant

New World, 78shamans, 78traditional Chinese use, 79

Medusa's head (Tillandsia caput medusae), 62meiosis, 31, 90metabolism, cactus, 69mistletoe, 64mitochondria, yeast cell, 91mold, bread molds, 83, 88

PPapaver rhoeas: See field poppypaper production, 76-77parasitism

fungus, 84plant, 64-65

parrot feather (Myriophyllum aquaticum), 10pathogenic fungus, 88-89peach, 54phaeophyte, 20phloem

angiosperms, 9leaves, 49root systems, 41stems, 43wood, 44-45

photosynthesis, 16-17algae, 20cactus, 68green revolution, 4-5leaves, 12, 48start, 37tree, 15water plants, 10

phycocolloide, 26phyllotaxis, 46pine, 56, 57pine cone: See conepine nut, 57Pinus longaeva: See bristlecone pinepitcher plant, 61plant

angiosperms, 9aquatic plants, 10-11Bromeliads, 62bud: See budcactus, 68-69carnivorous: See carnivorous plantcells, 16-17cellulose, 16classification, 8-9, 50common characteristics, 8conifers: See conifer

dioecious, 9energy source, 16environmental dangers, 5epiphytes, 62-63, 64-65evolutionary adaptations, 12-13, 65first true leaf, 37first twenty days, 37flower development, 37flowerless, 56giant, 13green revolution, 4-5growth rate, 7gymnosperms, 9history, 5hormones, 36lack of chlorophyll, 65lack of movement, 8land conquest, 12leaves: See leaflife cycle, 38-39medicinal, 78-79monocotyledons (monocots), 9naked seed (gnetophyta; gymnosperma), 9nearest relatives, 6number of species, 4, 8parasitic, 64-65photosynthesis: See photosynthesispines: See pinepoisonous: See poisonous plantpollination: See pollinationroot system, 12, 32-33seedless, 8seeds: See seedskin membrane, 12stemless, 13stems, 42-43tissues, 16-17tomato, 72-73toxic: See poisonous planttrees: See treeveined, 46water, 10-11wetland, 11

plant stem, 42-43cactus, 68

See also tree trunkpneumatophore, 11poison hemlock (Conium maculatum), 70poison ivy (Toxicodendron radicans), 71poisonous fungus, 86-87poisonous mushroom, 84-85, 87poisonous plant, 70-71pollination, 52-53

plants with seeds, 38Polygonum sp.: See knotweedpome, 54poppy, field: See field poppypotato, common, 42pressing, olive oil production, 75psilophyta, 8pulp, paper, 76

Q-RQuercus sp.: See oakrecaulescence, 46raceme, 66red cabbage, 46red marine algae (Rhodomela sp.), 8red spider mite (Tetranychus turkestani),

tomatoes, 72reproduction

algae, 22-23ferns, 32-33flowers, 38-39mosses, 31mushrooms, 85pollination, 52-53seedless, 8seeds, 36-37sexual, 9yeast, 91

Rhizopus nigricans: See black bread moldRhodomela sp.: See red marine algaerhodophyte, 21rice, 4Ricinus communis: See castor beanroot system, 40-41

monocotyledon (monocot)root systems, 40flowers, 50orchids, 9wood, 45

moss, 30-31epiphytes, 62oak, 15rhizoids, 8sphagnum, 8, 12

motherwort (Leonurus cardiaca), yin, 79multiple fruit, 55mushroom, 80-87

white, 9Myriophyllum aquaticum: See parrot featherMyzus persicae: See green peach aphidNative American, medicinal plant use, 78Nepenthes mirabilis, 61nettle, tomatoes, 72nightshade: See deadly nightshadenucleus, yeast cell, 91nut

acorn, 15dry fruit, 55

Ooak (Quercus sp.)

anatomy, 14-15plant adaptations, 13

Oenanthe crocata: See water dropwortoil press, olive oil production, 75olive (Olea europaea), 74olive oil, 74-75Ophrys apifera, 52-53orange, 54-55orchid,

classification, 9epiphytes, 62pollination, 52-53

orchid bee, 52-53osmosis, 41oxygen, 16

100 INDEX

cactus, 69dicotyledon, 50epiphyte, 62ferns, 32-33floating, 11geotropism, 36growth, 15land adaptation, 12monocotyledon, 51oak, 15parasitic plants, 65primary root, 37secondary, 37

rush, horsetail, 8rye, ergot, 86

Ssage: See clary sageSagittaria sagittifolia: See arrowheadsago pondweed, 10Saint Anthony's fire (ergotism), 86salt, 25Salvia sclarea: See clary sagesaprobe fungus, 84Sargasso, 26Sarracenia sp., 61season, trees, 15seaweed

harvest, 18-19not plants, 18phaeophytes, 20thallus, 20types, 20-21

seed, 36-37distribution, 39fruit, 39, 54-55orchid production, 53pollination, 34-35seedless plants, 8See also spore

sequoia: See giant sequoiaSequoiadendron giganteum: See giant sequoia

shaman, 78simple fruit, 54simple leaf, 48Sitka spruce, 9skin membrane, 12Socrates, 70soil

mosses, 31tomato cultivation, 72tree cultivation, 76

Solanum lycopersicum: See tomatosolar energy, conversion to chemical energy, 16Sonchus acaulis: See stemless sow-thistlesow-thistle, stemless, 13spadix, 66sphagnum moss, 8, 12spike (flower type), 66spikemoss, 8spore

algae, 22-23ferns, 32-33Fungi, 82-83lichen symbiosis, 29mosses, 30-32mushrooms, 84-85pathogenic molds, 88-89seedless plants, 8See also seed

sporophytealgae, 23mosses, 30-32

stem: See plant stemstemless sow-thistle (Sonchus acaulis), 13strangler fig (Ficus nymphaeifolia), 64submerged plant, 11sundew, 61sunflower, 66-67sweet potato white fly (Bemisia tabaco),tomatoes, 72sweet violet (Viola odorata), 13sycamore maple (Acer pseudoplatanus L.),

46-47symbiosis

lichens, 29Fungi, 84

U-Vumbel, 66Utricularia vulgaris: See bladderwortvacuole, yeast cell, 91Venus flytrap (Dionaea muscipula), 58-59Victoria cruciana: See tropical water lilyViola odorata: See sweet violetviolet, sweet, 13virgin olive oil, 75

Wwalnut (Juglans sp.), 13war flower, 71water

aquatic plants, 10-11hydroponic cultivation, 73paper production, 76, 77photosynthesis, 16

water dropwort (Oenanthe crocata), 70water lily, tropical, 10water plant: See aquatic plantwetland plant, 11wheat (Triticum sp.), 9white mushroom (Agaricus bisporus), 9wine, 90wood, 44-45

conifer, 56paper pulp, 76-77tree anatomy, 14-15

wort, 8

X-Yxylem

angiosperms, 9leaves, 49root systems, 41stems, 43

wood, 44-45yeast, 90-91yellow floating heart, 10yellow seaweed, 20

Zzoospore, 22Zygomycota (Zygomycetes), 83

fdf dsdfsdaf

TTasmanian bluegum: See Eucalyptus globulusTaxodiaceae: See cedartendril, 49terrestrial algae, 24-25Tetranychus turkestani: See red spider mitethallus, 20thistle: See artichoke thistle; stemless sow-thistlethylakoid, 17Tilia sp.: See lindenTillandsia caput medusae: See Medusa's headtoadstool, 80-81tomato (Solanum lycopersicum), cultivation, 72-73Toxicodendron radicans: See poison ivytracheophyte, 46tractor, tree cultivation, 76transgenic crop, tomatoes, 72-73transplanting

tomatoes, 72trees, 76

tree, 14-15classification, 9conifer, 56-57dendrochronology, 44distinguishing characteristics, 13earliest known, 45giant sequoia, 6-7, 13growth rings, 15know species, 45nuts, 55oldest, 45olive, 74tallest, 13, 45trunk: See tree trunkwood, 44-45

tree trunk anatomy, 14-15wood, 44-45

Triticum sp.: See wheattropical water lily (Victoria cruciana), 10tuber, 42Typha sp.: See cattail


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Plants, Algae, and Fungi