Plant PartsPlant Parts

Root systems:Root systems:A root system is the  A root system is the  network off all the network off all the roots of of a a plant; the ; the system of of roots and related roots and related organs that a plant develops.that a plant develops.

What are the types of root What are the types of root systems?systems?-Taproot: one main root, has no nodes◦(carrot, evergreen, kochia)

-Fibrous root: many nodes, branching root system (grasses)

DifferencesDifferencesTaprootSurvive Drought

BetterTend to grow

straight downVery thick center

main root

FibrousAre thin and hair

likeUsually shallowWill typically dry

out easilyMultiple root

systems

Root SystemsRoot SystemsRoot cap- outermost

part of a root◦ Tough cells that

penetrate the soil◦ Pushes through soil

partialsXylem – carry water

and mineral travel up the stem

Phloem – manufactured food travels down

Root hairs are small microscopic roots

Area of cell division◦ Allows roots to grow

longer◦ New cell replace

worn away cellsArea of cell

elongation◦ Between the root

cap and the plan base

◦ Cells become longer◦ Cells become

specialized

To help prevent soil erosion, which To help prevent soil erosion, which root system would be best?root system would be best?

Fibrous

Stem SystemsStem Systems

What are the functions of What are the functions of stems?stems?1) transport water, nutrients, sugars

2) support leaves, flowers and fruit

3) store food

Types of StemsTypes of Stems

Stem TypesStem TypesWoody:Tough and

winter hardy; often covered with bark

Herbaceous:Succulent; often

green; will not over winter in many climates

What are the types of What are the types of stems?stems?

1) Woody Stem: trees, shrubs, woody perennials

2) Grass Stem: hollow or filled

3) Herbaceous Stem: like woody but softer (clover, alfalfa)

4) Modified Stem: are plants like corms, rhizomes, and tubers (potatoes, ginger, and bulb plants)

Types of Modified StemsTypes of Modified StemsBulbs: (onion)Tubers: (potato)Stolons/Runners: above ground

runner (strawberry)Rhizomes: below ground runners

(field bindweed or creeping jenny)Tendrils: different types of vines

have these to latch onto things (grapes)

Cladophylls: (prickly) most cacti fall under this category

What are the parts of a What are the parts of a plant?plant?

Xylem and Phloem made up of parenchyma cells

Node: swollen part of stem where buds form (leaves or stems grow here)

Internode: stem tissue between nodes

What are the parts of a What are the parts of a plant?plant?Epicotyl: all of plant formed above

cotyledonary nodeCotyledons: leaves formed at first node

(cotyledonary node)New shoots or bud normally grow out of

the axilAxil is the upper angle above a leaf or

flower stem, and the stalkLenticels are pores that allow for gas

exchange to pass

What are buds?What are buds?special tissue on stems that can

grow into new plant parts

Leaf SystemsLeaf Systems

What are leaves?What are leaves?

undergo photosynthesis, exchange gases

Manufactures food for the plant by using light energy◦Converts sunlight into food

What are leaf margins?What are leaf margins?is the boundary area extending along the edge of the leaf. There are lots of different types of leaf margins that are important for plant identification

Common TypesCommon Types The basic types of margins are:

Entire:  having a smooth edge with neither teeth nor lobes.

Toothed :  having a saw like margin with small tooth that can vary in size (from very small to medium), in sharpness (from needle-like to soft) and in shape (from rounded to points).

Lobed: having some type of indentation toward the midrib that can vary in profundity and shape (rounded or pointed) and the incisions (sinus) go less than halfway to the midrib.

Parted (or cleft):  having some type of indentation toward the midrib that can vary in profundity and shape (rounded or pointed) and the incisions (sinus) go more than halfway to the midrib.

What is the difference between a What is the difference between a simple leaf and a compound leaf?simple leaf and a compound leaf?

simple leaf = 2 parts (leaf blade and petiole)

Petiole is the stem of the leaf, may or may not have one

Petiole

Leaf

Blade

What is the difference between a What is the difference between a simple leaf and a compound leaf?simple leaf and a compound leaf?

Compound leaf: leaf blade divided into leaflets

What are the different types What are the different types of compound leaves?of compound leaves?Palmately compound

What are the different types What are the different types of compound leaves?of compound leaves?Pinately compound

Types of Leaf Bud Types of Leaf Bud arrangementsarrangements

Buds are described Buds are described according to:according to:

1) structures into which they grow◦-Vegetative: leaves or stems◦-Floral: flowers◦-Mixed: both

2) where buds appear on stem◦-Apical: tips of stems

-if floral = bush -if vegetative = vine

◦-Axillary: where leaf joins stem◦-Adventitious: near wounds

Bud ArrangementsBud Arrangements◦3) How are Buds arranged?◦Alternate (alfalfa)◦Opposite (beans)◦Whorled (not common)

Leaf Shapes, Venation, Leaf Shapes, Venation, Apices and bases Apices and bases

Leaf Shapes…….Leaf Shapes……. In botany there are many terms, usually derived from Latin, used to describe the shape

of a plant leaf. The following are some of the basic ones dealing with leaf blade shapes

General overwiew:

Acicular: Having the shape of a needle

Cuneate: Broad and truncate at the summit, narrowly triangular, and tapering toward the base;

Deltoid: Triangular in outline, suggesting a capital delta.

Lanceolate: Lance-shaped, tapering from a broad base to an apex; much longer than wide

Ovate: Egg-shaped with the broadest part toward the base (note that obovate is the reverse relative)

Obovate: Stem attaches to tapering point petiole attachment to the blade)

Cordate: Heart shaped with a basal sinus.

Peltate: Shield shaped with the petiole not attached at the blade margin (peltata): Rounded, stem underneath

Scale leaf: Small sharp-pointed leaf with a broad base. They usually overlap on the stem.

Leaf Bases, Venation, and Leaf Bases, Venation, and ApicesApices The leaf base is the lowest  part of a leaf  lamina that is

near the petiole.       Leaves bases vary greatly from plant to plant and are useful

in classification and identification. Bilateral symmetry is typical. However, when the leaf shows asymmetry at the base this is known as an oblique leaf base.

The outer end or apex (Apices) of a leaf  lamina that is opposite the petiole.      

 Leaves apexes vary greatly from plant to plant and are useful in classification and identification.

The venation is the characteristic arrangement of veins in a leaf.

  There are lots of different types of leaf venation that are important for plant identification.

The term venation refers to how veins are distributed in the leaf blade

Leaf FunctionsLeaf FunctionsStomata: pores in the

stems that allow gas exchange

Guard cells open and close the stoma in a leaf

Chloroplasts give the leaf its strength and are the site for food production

Plant cell gives the leaf its strength and site for food production

What process manufactures food in the leaves?

PhotosynthesisThe cuticle is the

topmost layerEpidermis is the

surface layer on the upper and lower side of the leaf

Mesophyll contains layers of palisades and spongy tissue

Lets Review A little…..Lets Review A little…..What are internodes?Name one type of Modified stem?Give an example of a tuber?What are the 2 leaf types?Name one leaf shape?What is venation?Give an example of a Taproot

plant?

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