Fern s.l. (Pteridophyta)
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta.Unlike mosses, they have xylem and phloem (making them vascular plants). They have stems, leaves, and roots like other vascular plants. Ferns reproduce via spores and have neither seeds nor flowers.
By far the largest group of ferns are the leptosporangiate ferns, but ferns as defined here (also called monilophytes) include horsetails, whisk ferns, marattioid ferns, and ophioglossoid ferns. The term pteridophyte also refers to ferns and a few other seedless vascular plants (see classification section below). A pteridologist is a specialist in the study of pteridophytes in a broader sense that includes the more distantly related lycophytes.
Ferns first appear in the fossil record 360 million years ago in the Carboniferous but many of the current families and species did not appear until roughly 145 million years ago in the late Cretaceous (after flowering plants came to dominate many environments).
Source: http://en.wikipedia.org/wiki/Fern | ||
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