It has two kinds of sporangia microsporangia and megasporangia.
Vegetative reproduction is by means of buds and tubers. The plant reproduces by vegetative and sexual means. There are four rows of leaves on stem two rows of small leaves and two rows of large leaves. The sporophyte is green and has adventitious roots. Morphologically the plant displays lot of variation. Common examples include:Ĭommonly known as spikemoss, Selaginella is found in moist and shady places. Thus the life cycle of pteridophyte gets completed. The zygote later develops into a multicellular sporophyte. The sperm in antheridia fuses with the egg in archegonia resulting in the formation of zygote. Male sex organ is called antheridia and female sex organ is called archegonia. Gamatophytes are multicellular and photosynthetic. Their growth is restricted to only few places. The prothallus (gametophyte) can grow only in moist and cool shady place. Under favourable conditions these spores germinate into small independent gametophytes called prothallus. Microspores produce male antheridia and megaspores produce female archegonia.
Some plants are heterosporous as they produce two kinds of spores micro spores and macrospores. The spores are produced by spore mother cells through meiosis. The plant produces spores which are carried away by wind to far off places. This is the dominant and longer phase than the gametophyte generation.
#What generation means spore bearing plant free
The haploid generation is the gametophyte which produces the gametes.īoth the sporophyte and gametophyte are independent and free living. The diploid generation is the sporophyte which produces the spores. Just like in the seed bearing plants and mosses there is a diploid generation alternating with a haploid generation. There is alternation of generation in the lifespan of pteridophytes. Sometimes the sporophylls form compact structures known as cones or strobili.Ī well-developed vascular system with xylem (for conduction of water) and phloem (for conduction of food) is present. Leaves may also have spores on the underside. Some pteridophytes have small leaves called microphylls (e.g lycopodium) and some have large leaves called megaphylls (e.g Pteris). The main plant body has well differentiated root, stem and leaves. They mainly thrive in moist and shady places. The word ‘pteridophytes’ comes from Greek word Pteron meaning feather and phyton meaning plants. More than 12000 species of pteridophytes are found on Earth. They do not produce flowers and seeds hence they are also called Cryptogams. Pteridophytes occupy a transitional position between bryophytes and spermatophytes. Carolus Linnaeus classified them under the group cryptogamae. Pteridophytes are the first terrestrial vascular plants.
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