Some interesting extracts from Wikipedia link (for pictures/ more details, pl. click on the link): http://en.wikipedia.org/wiki/Fern
Ferns are vascular plants <http://en.wikipedia.org/wiki/Vascular_plant>differing from the more primitive lycophytes <http://en.wikipedia.org/wiki/Lycophyte> by having true leaves<http://en.wikipedia.org/wiki/Leaf>(megaphylls). They differ from seed plants <http://en.wikipedia.org/wiki/Seed_plant> (gymnosperms<http://en.wikipedia.org/wiki/Gymnosperm>and angiosperms <http://en.wikipedia.org/wiki/Angiosperm>) in their mode of reproduction—lacking flowers and seeds <http://en.wikipedia.org/wiki/Seed>. Like all other vascular plants, they have a life cycle<http://en.wikipedia.org/wiki/Biological_life_cycle>referred to as alternation of generations <http://en.wikipedia.org/wiki/Alternation_of_generations>, characterized by a diploid <http://en.wikipedia.org/wiki/Diploid> sporophytic <http://en.wikipedia.org/wiki/Sporophyte> and a haploid<http://en.wikipedia.org/wiki/Haploid> gametophytic <http://en.wikipedia.org/wiki/Gametophyte> phase. Unlike the gymnosperms and angiosperms, the ferns' gametophyte is a free-living organism. Life cycle of a typical fern: 1. A sporophyte <http://en.wikipedia.org/wiki/Sporophyte> (diploid<http://en.wikipedia.org/wiki/Diploid>) phase produces haploid <http://en.wikipedia.org/wiki/Haploid> spores<http://en.wikipedia.org/wiki/Spore>by meiosis <http://en.wikipedia.org/wiki/Meiosis>; 2. A spore grows by mitosis into a gametophyte<http://en.wikipedia.org/wiki/Gametophyte>, which typically consists of a photosynthetic prothallus<http://en.wikipedia.org/wiki/Prothallus> 3. The gametophyte produces gametes<http://en.wikipedia.org/wiki/Gametes>(often both sperm <http://en.wikipedia.org/wiki/Sperm> and eggs<http://en.wikipedia.org/wiki/Ovum>on the same prothallus) by mitosis <http://en.wikipedia.org/wiki/Mitosis> 4. A mobile, flagellate <http://en.wikipedia.org/wiki/Flagellum> sperm fertilizes an egg that remains attached to the prothallus 5. The fertilized egg is now a diploid zygote<http://en.wikipedia.org/wiki/Zygote>and grows by mitosis into a sporophyte (the typical "fern" plant). Like the sporophytes of seed plants, those of ferns consist of: - Stems <http://en.wikipedia.org/wiki/Plant_stem>: Most often an underground creeping rhizome <http://en.wikipedia.org/wiki/Rhizome>, but sometimes an above-ground creeping stolon<http://en.wikipedia.org/wiki/Stolon>(e.g., Polypodiaceae <http://en.wikipedia.org/wiki/Polypodiaceae>), or an above-ground erect semi-woody trunk (e.g., Cyatheaceae<http://en.wikipedia.org/wiki/Cyatheaceae>) reaching up to 20 m in a few species (e.g., *Cyathea brownii* on Norfolk Island <http://en.wikipedia.org/wiki/Norfolk_Island> and *Cyathea medullaris* in New Zealand <http://en.wikipedia.org/wiki/New_Zealand>). - Leaf <http://en.wikipedia.org/wiki/Leaf>: The green<http://en.wikipedia.org/wiki/Green>, photosynthetic <http://en.wikipedia.org/wiki/Photosynthesis> part of the plant. In ferns, it is often referred to as a frond<http://en.wikipedia.org/wiki/Frond>, but this is because of the historical division between people who study ferns and people who study seed plants, rather than because of differences in structure. New leaves typically expand by the unrolling of a tight spiral called a crozier or fiddlehead <http://en.wikipedia.org/wiki/Fiddlehead>. This uncurling of the leaf is termed circinate vernation<http://en.wikipedia.org/wiki/Circinate_vernation>. Leaves are divided into three types: - Trophophyll: A leaf that does not produce spores, instead only producing sugars by photosynthesis. Analogous to the typical green leaves of seed plants. - Sporophyll <http://en.wikipedia.org/wiki/Sporophyll>: A leaf that produces spores. These leaves are analogous to the scales of pine cones or to stamens and pistil in gymnosperms and angiosperms, respectively. Unlike the seed plants, however, the sporophylls of ferns are typically not very specialized, looking similar to trophophylls and producing sugars by photosynthesis as the trophophylls do. - Brophophyll: A leaf that produces abnormally large amounts of spores. Their leaves are also larger than the other leaves but bear a resemblance to trophopylls. - Roots <http://en.wikipedia.org/wiki/Root>: The underground non-photosynthetic structures that take up water and nutrients from soil<http://en.wikipedia.org/wiki/Soil>. They are always fibrous<http://en.wikipedia.org/wiki/Fibrous_root_system>and are structurally very similar to the roots of seed plants. The gametophytes of ferns, however, are very different from those of seed plants. They typically consist of: - Prothallus: A green, photosynthetic structure that is one cell thick, usually heart or kidney shaped, 3–10 mm long and 2–8 mm broad. The prothallus produces gametes by means of: - Antheridia <http://en.wikipedia.org/wiki/Antheridium>: Small spherical structures that produce flagellate<http://en.wikipedia.org/wiki/Flagellum>sperm. - Archegonia <http://en.wikipedia.org/wiki/Archegonium>: A flask-shaped structure that produces a single egg at the bottom, reached by the sperm by swimming down the neck. - Rhizoids <http://en.wikipedia.org/wiki/Rhizoid>: root<http://en.wikipedia.org/wiki/Root>-like structures (not true roots) that consist of single greatly-elongated cells, water and mineral salts are absorbed over the whole structure. Rhizoids anchor the prothallus to the soil. One difference between sporophytes and gametophytes might be summed up by the saying that "Nothing eats ferns, but everything eats gametophytes." This is an over-simplification, but it is true that gametophytes are often difficult to find in the field because they are far more likely to be food than are the sporophytes. 2009/4/4 Prashant awale <[email protected]> > Since we are on the topic of fern, i am sharing these 2 photographs which i > had taken at Mizoram during November-2008. > > best wishes > Prashant.. > > > On Sat, Apr 4, 2009 at 1:22 PM, bindu kapadia <[email protected]> wrote: > >> Fern tree are generally found in the North at specific height. >> I had seen them in Skkim and also on the way to Har ki Doon. >> 1st pic in Kalimpong and the 2nd on the trails Lava >> Regards, >> Bindu >> >> >> > > > > -- With regards, J.M.Garg "We often ignore the beauty around us" Creating Awareness about Indian Flora & Fauna: http://en.wikipedia.org/wiki/User:Jmgarg1 For learning about our trees & plants, please visit/ join Google e-group (Indiantreepix) http://groups.google.co.in/group/indiantreepix?hl=en --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "indiantreepix" group. 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