Major Plant Division

BYROPHYTES
first major plant divisions
three phyla of byrophytes:
mosses, liverworts, and hornworts
Mosses
-most familiar byrophytes.
-Byrophyte gametophytes are a few cells thick
-come from meristems.
-liverworts, hornworts, and mosses came about independently early in plant evolution.
-gametophyte is the dominant generation in the life cycles.

GYMNOSPERMS
-conifers
-lack enclosed ovaries
-gymnosperm ovules and seeds develop on the scales of cones.
-The four phyla of gymnosperms are ginkgo, cycads, gnetophytes, and conifers.
-550 species of conifers

PTERIDOPHYTES: SEEDLESS VASCULAR PLANTS
-phylum Lycophyta and phylum Pterophyta.
-Pteridophytes provide clues to the evolution of roots and leaves.
-The tissue system in this root is similar to that of the stems of early vascular plants.
-Lycophytes(modern vascular plants), have small leaves with a single branched vein(evolved from tissue flaps on the surface of stems)
-leaves are known as microphylls which means "small leaves".
-leaves of other vascular plants are known as megaphylls, means "large leaves".
-lack seeds, but provide steps to the evolution of life cycle adaptations

ANGIOSPERMS
-flowering plants
-vascular seed plants
-produce flowers and fruits.
-placed in a single phylum(Anthophyta)
-the monocots and the dicots,monocots have leaves with veins running straight across and dicots have leaves similar to that of an oak leaf.
-flower is an angiosperm structure thats specializes in reproduction.
-Fruits help spread seeds of angiosperms.