Plant Phyla But before we get into phyla

Plant Phyla

But before we get into phyla. . . n To what domain do plants belong? n EUKARYA!! n To what kingdom do plants belong? n Plants (Plantae) n What are some characteristics that ALL plants share? – – Cell nuclei (Eukarya) Cell walls Multicellular Photosynthesis

Evidence suggests that green algae is the ancestor of modern plants. Why? n Plants live on land in water. n Adaptations that allow plants to live on land include: n Mechanisms for retaining moisture: cuticle and stomata (see p. 614) n Means of transporting resources: vascular system (see p. 614) n Able to grow upright: lignin (see p. 614) n Mechanisms for reproduction: pollen and seeds (see p. 614)

Classifying plants n Plants are classified into four main groups: 1. Mosses and Liverwort (Bryophyta) 2. Ferns (Pteridophyta) 3. Conifers (Gymnosperms) 4. Flowering Plants (Angiosperms) – All are different in appearance, structure and behaviour.

Mosses - Bryophyta n Mosses are non-vascular plants -- they cannot transport fluids through their bodies. n Instead, they must rely on surrounding moisture to do this job for them. n Though small in stature, mosses are very important members of our ecosystem. n They lay the foundations for other plant growth, prevent erosion, and contribute to the lush green appearance of many forested areas.

Mosses - 2 n The 24, 000 bryophyte species, sometimes grouped into a single phylum are now grouped in three phyla: 1. Mosses (Bryophyta), 2. Liverworts (Hepatophyta) and 3. Hornworts (Anthoceraphyta). n They reproduce by spores, never have flowers, and can be found growing on the ground, on rocks, and on other plants.

Mosses

Liverworts and Hornworts

The Fern - Pteridophyta n Ferns have a vascular system to transport fluids through their bodies but like the mosses, they reproduce from spores rather than seeds. n The main phylum, the Ferns (Pteridophyta) includes around 12, 000 species. n Three other phyla are included as fern allies: the Horsetails, Club Mosses and Whisk Ferns n Ferns also have a gametophyte and sporophyte stage, but the gametophyte stage is very short.

Conifers - Gymnosperms n n n The gymnosperms reproduce from seeds instead of spores. The seeds, however, are "naked" (Greek: gummnos) -- not covered by an ovary. Usually, the seed is produced inside a cone-like structure such as a pine cone which is why they are called "conifer. " Some conifers, such as the Yew and Ginko, produce their seeds inside a berry-like structure. Conifers are fairly easy to identify: In addition to cones, these trees and shrubs typically have needlelike, scale-like or awl-like leaves. And they NEVER have flowers.

Conifers - 2 n n n Approximately 600 species are counted as conifers including the pines, firs, spruces, cedars, junipers, and yew. Species within the conifer ranks give us pine nuts -- pesto's magic ingredient -- as well as juniper berries for gin. Conifer allies include three small phyla containing fewer than 200 species all together: Gingko (Ginkophyta) Cycads (Cycadophyta) ; And herb-like cone-bearing plants (Gnetophyta) such as Ephedra.

Conifers

Angiosperms (Flowering Plants): n Angiosperms have flowers and fruit. n A flower is the reproductive structure of flowering plants, and they protect a plant’s gametes and fertilized eggs (just like woody cones do for most gymnosperms). n A fruit is the mature ovary of a flower. Examples: apples and peaches

Further classification of flowering plants… n Botanists classify flowering plants into two groups based on two basic kinds of seeds: seeds with one or two cotyledons. n A cotyledon is an embryonic leaf inside a seed. They are often called “seed leaves. ” n This develops into a seedling, and then eventually a fully developed plant. n The two groups based on seeds are monocots and dicots.

Monocots n Monocots are flowering plants whose embryos have one seed leaf. n They generally have parallel veins in long, narrow leaves (such as in an iris or lily). n Their flowers usually occur in multiples of 3, and bundles of vascular tissue are scattered throughout the stem. n Examples: corn, wheat, rice, grasses, irises, and lillies

Dicots n Dicots are flowering plants whose embryos have two seed leaves. n They have leaves with netlike veins. n Flowers usually occur in multiples of four or five, and bundles of vascular tissue arranged in rings. n Examples: deciduous trees, peanuts

Quick Review n Main types of plants: mosses, ferns, gymnosperms, and angiosperms n Mosses: nonvascular; reproduce via spores n Ferns: vascular; reproduce via spores n Gymnosperms: nonflowering; reproduce via “naked seeds” meaning they do not produce fruit n Angiosperms: flowering; reproduce via seeds that are protected in mature ovaries called fruit