| About 97% of living Pteridophytes are ferns. In
fact, there are probably about 12,000 species of ferns in the world,
most of these found in the tropics. Unlike the fern allies which are a
relic group, the ferns are highly successful and are virtually found
in any habitat flowering plants are found. |
Tree fern (Cyathea arborea) |
| There are climbing ferns, aquatic ferns, tree ferns, filmy ferns with leaves just one cell thick, epiphytic ferns and, of course, ferns of a more conventional herbaceous habit. | 
Floating fern (Azolla sp.) |
 Epiphytic Bird's nest fern |
These occupy a wide spectrum of habitats in the tropics and temperates from alpine through wet and dry zones |
| In ferns, as for other pteridophytes,
the sporophyte is the dominant generation to the extent that this is
the generation recognised as a fern. The gametophyte is short-lived, a
few mm in size and virtually hidden from view. |
 Sporophyte |
¡@ Gametophyte |
Two features of ferns especially stand out ;-
| Large, typically pinnate, leaves - often termed fronds |  |
|
| Circinate vernation Term used to describe the protective coiling of young fern leaves into a spiral like a shepherd's crook or bishop's crozier or a fiddle head. | .  |
Index about Animal Kingdom birds mammals Amphibians reptiles fish
Plant Kingdom monocotyledons dicotyledons Gymnosperms Ferns Algae Fungi
gaseous exchange breathing system Respiration Experiment ( ©I§l§@¥Î¹êÅç ) Smoking and your health
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