Ophioglossum
Common adder's tongue ( Ophioglossum vulgatum )
The snake tongues ( Ophioglossum ) are a genus of ferns from the family of adder's tongue plants ( Ophioglossaceae ).
- 5.1 Literature
- 5.2 External links
Description
Like all plants of the family have a the snake tongues or few basal leaves, which spring from an underground, short stems. The leaves are divided to the base, or at least far down into two sections, a flat, sterile " lamina ", the Trophophyll, the one commonly referred to as " the blade " and a fertile part of the sporophyll.
The Trophophyll is at the viper tongues always undivided and entire. Its shape is tongue- shaped, lanceolate, heart-shaped to. His reason includes the sporophyll scheidig, so that the two leaf parts often seem to separate only far above the ground at first glance. The flat part of the Trophophylls may be sessile or pedunculated. Its size varies considerably in the different species.
The net-like venation of Trophophylls seems to indicate that it is more of a derived as an original Farngruppe at the snake tongues.
This is not always present sporophyll is always long stalks. The sporangia are arranged on it in two vertical rows and laterally fused, so that it acts as if they were sunk in the sporophyll. The latter is narrow-linear and ends in most species more or less pointed.
In most species in temperate latitudes only one sheet is formed per year in tropical species of the genus sometimes up to five.
Distribution and habitat requirements
The genus has a worldwide distribution, with most species occur in the tropics and subtropics.
Except for two kinds every snake tongues grow on moist to wet soil on prairie. You will probably often overlooked because they see in a sterile condition the cotyledons of monocots similar.
The two mentioned not growing on earth species are Ophioglossum pendulum and Ophioglossum palmatum. These grow as epiphytes and differ also in the habit a lot of the other types, which is why they are often outsourced as Ophioderma pendula or Cheiroglossa palmata in its own monotypic genera.
Species
The genus includes 20-50 species worldwide.
European Species
In Europe, four species are:
- Ophioglossum azoricum C. Presl, is found in Western Europe and very rare in Central Europe.
- Ophioglossum lusitanicum L., occurs in the Mediterranean region and in Western Europe.
- Ophioglossum polyphyllum A. Brown, occurs in Africa and South Asia, but also in Portugal.
- Common adder's tongue ( Ophioglossum vulgatum L.) occurs in almost all of Europe, North America, Asia, Australia and Africa.
Other types (selection)
- Ophioglossum californicum Prantl, occurs in California and Mexico.
- Ophioglossum palmatum L. (syn.: Cheiroglossa palmata (L. ) C. Presl ), occurs in Central and South America and Madagascar.
- Ophioglossum pendulum L. (syn.: Ophioderma pendula (L. ) C. Presl ), is found in several subspecies in Asia and Polynesia.
- Ophioglossum reticulatum L., occurs in South Asia.
Others
The snake tongues, the number of chromosomes is strikingly high. The South Asian Art Ophioglossum has reticulatum with 2n = 1260 even the highest chromosome number in the entire plant kingdom.
All species are mykotroph adder's tongue, so instructed in their lives more or less strongly to the coexistence with mushrooms. For example, lack the roots, the root hairs, suggesting that mycorrhizal fungi have taken over their function. Furthermore, the underground prothallus remains chlorophylllos and not alone viable in the rule. In some species, finally, the sporophyll is almost completely reduced.