plants that have a true vascular system (cormus) but did not produce seeds for reproduction. Instead of seeds, the plants are still using the spores as a means of generative propagation, like moss and fungi.
world, except the eternal snow and dry areas (desert). Total species known to almost 10,000 (estimated 3000 of whom grew up in Indonesia), mostly grown in the humid wet tropics. These plants tend to be resistant to the conditions of limited water, may follow the behavior of fathers in the Carboniferous era, also known as the golden age because of ferns dominated the earth's forests. Litter of forest vegetation in this age of the fossilized right now as a coal mined people.
Form a variety of ferns, there is a tree (tree nails, usually unbranched), epiphytes, floating in the water, hidrofit, but usually a terna with rhizomes that spread in the soil or humus and ental (English Frond) supporting the leaf varying sizes (up to 6 m). Ental young always roll up (like the handle of a violin) and became a hallmark of ferns. Frond is almost always compound leaves. Common ferns dominate the vegetation of a place so as to form a large shrub and suppress other plants.
Life cycle (metagenesis)
Life cycle of ferns known descendants of rotation, which consists of two main phases: the gametophyte and sporophytes. Ferns are easy to see is a form of phase sporophytes because it produces spores. Phase is called the gametophyte generation forms protalus (prothallus) or protalium (prothallium), in the form of small plants in the form of sheet is green, moss-like liver, is not rooted (as his successor but has rizoid), not trunked, no leaves. Prothallium grow from spores that fell in a humid place. Of developing prothallium anteridium (antheridium, spermatozoid producing organs or male sex cell) and arkegonium (archegonium, the organ producing ova or egg cells). Absolute conception of water as a medium need help to move toward the archegonium spermatozoid. The fertilized ovum develops into a zygote, which in turn grow into new ferns.
Seed plants (Spermatophyta) also have a cycle like this but it has evolved even further so that the gametophyte stage is not independent. Spores are produced directly grow into stamens or embryo sac.
Traditionally, Pteridophyta includes all cormophyta spores, except liver moss, moss horn, plants and moss. In addition to the true nail (Filicinae class), including horsetail (Equisetinae), rane and wire nails (Lycopodiinae), Psilotum (Psilotinae), and Isoetes (Isoetinae). Even now the study of these groups are called pteridologi and experts called pteridolog.
Smith et al. (2006) propose the revision that is strong enough based on morphological and molecular data. Based on this new classification, Lycophyta (rane, wire nails, and Isoetes) are the first vascular plants apart from the others, while ferns and seed plants are in other groups. Further seen that all the remaining kcormophyta spores merged into one large group, which is said to be worthy members of the divisio ferns (Pteridophyta). From the results of this revision is also seen that a number of ferns that once regarded as primitive nail (like Psilotum) was more closely allied with nails pointed out the sky (Helminthostachys), while horsetail (Equisetum ') as close to the real nail against Marattia.
Thus, under this new classification, ferns can be grouped as follows.
with one class: Lycopsida.
with four monophyletic classes:
* Psilotopsida, including Ophioglossales.
* Polypodiopsida (= Pteridopsida, Filicopsida)
This last division includes all the plants commonly known as real nails or nail properly. Here is the complete classification by Smith et al. (2006):
Interest Ophioglossaceae (including Botrychiaceae, Helminthostachyaceae)
Psilotaceae tribes (including Tmesipteridaceae)
Class Equisetopsida [= Sphenopsida]
Marattiaceae tribes (including Angiopteridaceae, Christenseniaceae, Danaeaceae, Kaulfussiaceae)
Class Polypodiopsida [= Filicopsida, Pteridopsida]
Hymenophyllaceae tribes (including Trichomanaceae)
Gleicheniaceae tribes (including Dicranopteridaceae, Stromatopteridaceae)
Dipteridaceae tribes (including Cheiropleuriaceae)
Anemiaceae tribes (including Mohriaceae)
Nation Salviniales (nail water)
Marsileaceae tribes (including Pilulariaceae)
Salviniaceae tribes (including Azollaceae)
Nation Cyatheales (tree nails)
Cyatheaceae tribes (including Alsophilaceae, Hymenophyllopsidaceae)
Lindsaeaceae tribes (including Cystodiaceae, Lonchitidaceae)
Dennstaedtiaceae tribes (including Hypolepidaceae, Monachosoraceae, Pteridiaceae)
Interest Pteridaceae (including Acrostichaceae, Actiniopteridaceae, Adiantaceae, Anopteraceae, Antrophyaceae, Ceratopteridaceae, Cheilanthaceae, Cryptogrammaceae, Hemionitidaceae, Negripteridaceae, Parkeriaceae, Platyzomataceae, Sinopteridaceae, Taenitidaceae, Vittariaceae)
Woodsiaceae tribes (including Athyriaceae, Cystopteridaceae)
Blechnaceae tribes (including Stenochlaenaceae)
Interest Dryopteridaceae (including Aspidiaceae, Bolbitidaceae, Elaphoglossaceae, Hypodematiaceae, Peranemataceae)
Lomariopsidaceae tribes (including Nephrolepidaceae
Polypodiaceae tribe (including Drynariaceae, Grammitidaceae, Gymnogrammitidaceae, Loxogrammaceae, Platyceriaceae, Pleurisoriopsidaceae)