Plants!!

They’re cool

Vascular vs. Nonvascular Plants

Seedless plants•Although most plants grow from seeds – nonvascular plants do not.•Nonvascular plants are usually only a few cells thick. •Instead of roots they have rhizoids to anchor them in place.•Water is absorbed directly through cell membrane.

Mosses•Most nonvascular plants are mosses. •Often grow on tree trunks, rocks, or on the ground. •Most are found in damp areas – but a few species have adapted to living in other types of climates.

Liverworts•Rootless plants with flattened leaf-like bodies.•Rhizoids are usually only one cell thick.•Originally thought to cure diseases of the liver.

Hornworts•Very small•Spores look like tiny cattle horns

Importance of nonvascular plants•Can grow in thin soils and places where other plants can’t grow.•Often the first plants to grow in new or disturbed environment. = pioneer species• Helps create enough soil and rock breakdown so that other

plants can grow.

Seedless Vascular Plants•Most common types: ferns, horsetails.•Around the time of the dinosaurs seedless vascular plants dominated the earth – were much larger.

Ferns•Have stems, leaves and roots. •Produce spores that are usually found on the underside of the fronds (fern leaves).

Club mosses

Horsetails•Spores from horsetails are produced in cone-like structures on the tips of stems.

Importance of Seedless Plants•Ancient seedless plants died and become submerged in water and mud before decomposing – eventually compacted and turned into coal. (took millions of years)

Seed Plants•Most plants you are familiar with are seed plants.•Most seed plants have stems, roots, leaves and vascular tissue.

•Seeds contain an embryo and stored food for the plant’s early development.

Seed plants are classified into two groups

1. Gymnosperms2. angiosperms

Gymnosperms•The oldest trees alive•Vascular plants that produce seeds which are not protected by fruit.•Do not have flowers – most leaves are needlelike or scaly.•Many gymnosperms are evergreens.

Angiosperms•A vascular plant that flowers and produces fruit.•Wide variety of fruits and flowers

Angiosperms are divided into two group

1. Monocots2. dicots

•Cotyledon – part of the seed often used for food storage.•Monocots have one cotyledon inside the seed.•Dicots have two cotyledons.

Monocots•Corn, rice, wheat, barley, bananas, pineapples.

Dicots•Peanuts, green beans, peas, apples, oranges.

Importance of seed plants•Wood•Clothing•Food•Angiosperms form the basis of the diets of most animals.