Plant Diversity
Plants are grouped according to major characteristics.
Non-vascular (Bryophytes)—have no internal transport system
for food or water. Must live in moist areas, and all are small.
(WHY?) Example: moss
Vascular—have a tube network inside the stem. (Advantage?)
Have true roots, stems and leaves.
Non-seed plants—reproduce by spores. Are simple and ancient
types of plants (they have been around since dinosaurs). Some are
vascular, some non-vascular. Examples: ferns, horsetails
Seed plants—reproduce by seeds. Advantage: Can survive harsh
conditions, have energy to begin growth. Examples: most plants.
Types of seed plants
Gymnosperms—“naked seeds”. Seeds are usually in cones, not
inside a fruit. Examples: cycads, gingkoes, pine, spruce, redwood.
Angiosperms—“covered seeds.” Fruits are ripened ovaries of
flowers. Examples: Anything with a flower.
Angiosperms are divided into two groups.
Monocots—have one seed leaf. Leaves have parallel veins. Roots
are fibrous (shallow and spreading). Many are annual or
biennial. Examples: grasses, grains, corn, lilies
Dicots—have two seed leaves. Leaves have net-like veins. Roots
are taproots (deep and concentrated). Many are perennial.
Ex.: most trees and shrubs, vegetables and garden flowers.
Dicots are further divided by their stem type.
Woody stems—make bark and have heartwood.
Herbaceous stems—have green stems (no bark/heartwood).