Essay Archive - Diverrsity of Plants
Diverrsity of Plants
Plants evolved more than 430 million years ago from multicellular green
algae. By 300 million years ago, trees had evolved and formed forests, within
which the diversification of vertebrates, insects, and fungi occurred. Roughly
266,000 species of plants are now living.
The two major groups of plants are the bryophytes and the vascular
plants; the latter group consists of nine divisions that have living members.
Bryophytes and ferns require free water so that sperm can swim between the male
and female sex organs; most other plants do not. Vascular plants have elaborate
wat....
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