CLASSIFYING CLASSIFYING PLANT GROUPSPLANT GROUPS

OCS BiologyOCS Biology

Mrs. BonifayMrs. Bonifay

PLANTSPLANTS

Scientists have identified more than Scientists have identified more than 260,000 260,000 kinds of plants.kinds of plants.

They classify plants according to whether They classify plants according to whether they have body parts such as they have body parts such as seeds, seeds, tubes, roots, stems, and leaves.tubes, roots, stems, and leaves.

The three main groups of plants are The three main groups of plants are seed seed plants, ferns, and mosses.plants, ferns, and mosses.

Vascular PlantsVascular Plants

Vascular plants have Vascular plants have tube-like cellstube-like cells. . These cells form tissue called These cells form tissue called vascular vascular tissue. tissue. The tissue forms tubes that The tissue forms tubes that transport food and watertransport food and water through the through the plant.plant.

Vascular means Vascular means “vessel” “vessel” oror “tube.” “tube.” Seed plants and ferns Seed plants and ferns are vascular are vascular

plants.plants...

Vascular PlantsVascular Plants

Vascular plants have well-developed Vascular plants have well-developed leaves, stems, and roots.leaves, stems, and roots.

Because of vascular tissue, these plants Because of vascular tissue, these plants can can grow largergrow larger because its leaves and because its leaves and stems stems do not need to be near waterdo not need to be near water..

Vascular tissue is Vascular tissue is thickthick and provides and provides supportsupport for a plant. This allows the plant for a plant. This allows the plant to to grow tallgrow tall..

Nonvascular PlantsNonvascular Plants

Nonvascular plants do not have Nonvascular plants do not have tube-like tube-like cells. cells.

Mosses Mosses are nonvascular plants.are nonvascular plants. These plants are These plants are shortshort and must have and must have

constant contact with constant contact with moisturemoisture.. These plants usually grow in These plants usually grow in dampdamp, ,

shady placesshady places on the ground and on the on the ground and on the side of trees and rocks.side of trees and rocks.

Seed PlantsSeed Plants

Seed plants are different from ferns and moss Seed plants are different from ferns and moss because they use seeds to because they use seeds to reproducereproduce..

A seed is a plant part that contains A seed is a plant part that contains a beginninga beginning plantplant and and stored foodstored food. The beginning plant is . The beginning plant is called an called an embryoembryo..

The seed has a The seed has a seed coatseed coat which holds in which holds in moisture.moisture.

Seed plants have the most advanced Seed plants have the most advanced vascular vascular tissuetissue of all plants with well-developed leaves, of all plants with well-developed leaves, stems, and roots.stems, and roots.

Seed PlantsSeed Plants

Seed plants come in many different sizes Seed plants come in many different sizes and shapes. This helps them and shapes. This helps them live in live in many different places.many different places.

Seed plants are the largest group of Seed plants are the largest group of plants. They are divided into two groups: plants. They are divided into two groups:

1. 1. flowering plantsflowering plants

2. 2. non-flowering plantsnon-flowering plants

AngiospermsAngiosperms

Flowering seed plants are called Flowering seed plants are called angiospermsangiosperms..

A A capsule, or fruitcapsule, or fruit, protects the seeds of , protects the seeds of angiosperms.angiosperms.

The fruit forms from part of the flower, The fruit forms from part of the flower, which comes in many which comes in many shapes and colorsshapes and colors..

AngiospermsAngiosperms

Angiosperms are divided into Angiosperms are divided into monocots monocots and dicots.and dicots.

Most angiosperms are dicots, which Most angiosperms are dicots, which contain contain two cotyledonstwo cotyledons (a structure in the (a structure in the seed that contains food for the seed that contains food for the developing plant).developing plant).

A bean is an example of aA bean is an example of a large dicot seed.large dicot seed.

Angiosperms/DicotsAngiosperms/Dicots

When a bean is planted, the plant When a bean is planted, the plant appears to have appears to have two leavestwo leaves. If you split a . If you split a bean apart, you may be able to see the bean apart, you may be able to see the two leavestwo leaves in the in the tiny embryotiny embryo..

If you look at the leaves of a dicot plant, If you look at the leaves of a dicot plant, the veins are the veins are branched or netlikebranched or netlike. This is . This is another property of a dicot.another property of a dicot.

Angiosperms/DicotsAngiosperms/Dicots

Most Most floweringflowering plants are dicots. plants are dicots. Animals eat dicots in the form of Animals eat dicots in the form of fruits fruits

and vegetables.and vegetables. Other examples of dicots are Other examples of dicots are oak trees, oak trees,

roses, sunflowers, and giant redwood roses, sunflowers, and giant redwood treestrees. .

Angiosperms/MonocotsAngiosperms/Monocots

Monocots have only Monocots have only one cotyledonone cotyledon.. When a monocot begins to grow from a When a monocot begins to grow from a

seed, only seed, only one leafone leaf appears. Also, the appears. Also, the veins in the leaf are veins in the leaf are parallelparallel..

Monocots include Monocots include grass, corn,grass, corn,

wheat, rice, and flowers suchwheat, rice, and flowers such

as lilies and orchidsas lilies and orchids..

GymnospermsGymnosperms

Non-flowering seed plants are called Non-flowering seed plants are called gymnospermsgymnosperms..

The seeds of gymnosperms are not The seeds of gymnosperms are not surrounded by fruit. The seeds are surrounded by fruit. The seeds are produced produced inside cones. inside cones. For example, For example, pine trees form on thepine trees form on the

scales of cones.scales of cones.

Conifers and Other Conifers and Other GymnospermsGymnosperms

The major group of gymnosperms is The major group of gymnosperms is conifersconifers, which are , which are cone-cone-bearingbearing gymnosperms. gymnosperms.

All conifers are All conifers are woody shrubs or treeswoody shrubs or trees.. Most conifers have Most conifers have green leavesgreen leaves all year. Because of this, they all year. Because of this, they

are called are called evergreens. evergreens. Conifers’ leaves are shaped like Conifers’ leaves are shaped like needles.needles. They They do not lose waterdo not lose water

as easily as broad leaves. They can live in dry places.as easily as broad leaves. They can live in dry places. Other gymnosperms include the Other gymnosperms include the ginkgo treeginkgo tree, which has , which has fan-fan-

shapedshaped leaves. They are able to survive leaves. They are able to survive pollution pollution better than better than other trees.other trees.

Seedless PlantsSeedless Plants

There are two main groups of seedless There are two main groups of seedless plants: plants: fernsferns and related plants, and and related plants, and mossesmosses and related plants. and related plants.

Ferns are Ferns are vascular plantsvascular plants, but do not , but do not have seeds.have seeds.

Mosses are Mosses are non-vascular plantsnon-vascular plants, and , and also do not have seeds.also do not have seeds.

FernsFerns

Like other vascular plants, ferns have Like other vascular plants, ferns have well-well-developed developed leaves, stems, and roots.leaves, stems, and roots.

The ferns’ leaves, or The ferns’ leaves, or frondsfronds, are usually large , are usually large and flat. They are divided into and flat. They are divided into leafletsleaflets that that spread out from a spread out from a center ribcenter rib..

On the underside of the fronds, you can see On the underside of the fronds, you can see small dots called small dots called sorisori. These are clusters that . These are clusters that contain the contain the reproductive cellsreproductive cells of the fern, called of the fern, called spores. spores. When the spores are ripe, the sori When the spores are ripe, the sori burst open and releaseburst open and release the spores into the air. the spores into the air.

FernsFerns

The The rhizomerhizome is a plant part that is a plant part that shootsshoots above ground and above ground and rootsroots below ground. below ground.

Fern spores that drop in a Fern spores that drop in a moist placemoist place, , produce a a tiny plant or rhizome.produce a a tiny plant or rhizome.

MossesMosses

MossesMosses are gymnosperms. They are non- are gymnosperms. They are non-vascular plants the do not have well- vascular plants the do not have well- developed leaves, stems, and roots.developed leaves, stems, and roots.

They do not have vascular tissue to transport They do not have vascular tissue to transport water, so they must live in water, so they must live in moist shady placesmoist shady places..

Mosses get water through root-like threads Mosses get water through root-like threads called called rhizoidsrhizoids..

Like ferns, mosses reproduce by Like ferns, mosses reproduce by sporesspores. . Mosses produce a great number of spores.Mosses produce a great number of spores.

Soil and Bog BuildersSoil and Bog Builders

Mosses can grow in places where other plants cannot Mosses can grow in places where other plants cannot root because they are so tiny.root because they are so tiny.

Mosses grow on Mosses grow on tree bark, rocks, and in thin soil.tree bark, rocks, and in thin soil. When moss plants die, they form When moss plants die, they form humus, humus, which is which is

made from made from dead plants and animalsdead plants and animals, and is very , and is very rich rich and helps plants grow.and helps plants grow.

A A bogbog is wet, spongy ground that is made from rotted is wet, spongy ground that is made from rotted moss and other plant matter.moss and other plant matter. Air Air does not reach the does not reach the dead plants and the lack of oxygen keeps the plants dead plants and the lack of oxygen keeps the plants from breaking down quickly. Over time, the plant from breaking down quickly. Over time, the plant matter becomes tightly pressed together and forms matter becomes tightly pressed together and forms peatpeat. . Peat mossPeat moss is used to enrich garden soil. is used to enrich garden soil.