Hymenophyllaceae

English Hautfarn ( Hymenophyllum tunbrigense )

The Hautfarngewächse or veil ferns ( Hymenophyllaceae ) are a family leptosporangiater ferns. They are the only members of the order Hautfarnartige ( Hymenophyllales ).

Features

The rhizomes are tender, creeping or partially erect, and have a protostele. The leaves are curled young. Your name have gotten the skin ferns because their leaf blade, apart from the leaf veins, only one cell layer thick. It therefore lacks stomata, but also the cuticle is not usually configured.

Another typical feature is the position of the sporangia. These are always on the leaf margin ( marginal), and not, as in most other ferns on the underside of leaves or leaf surface. The spores are green.

The prothallia are in the skin ferns always band-shaped and einzellschichtige, in many species even branched thread-like structure, reminiscent of the protonema of mosses. Even in the soft skin ferns from the other ferns.

The basic number of chromosomes can be varied and x = 11, 12, 18, 28, 32, 33, 34 or 36 be.

Occurrence

Hautfarngewächse occur mainly in tropical rainforests. They grow terrestrial and epiphytic. In Central Europe, there are only two species that grow as great rarities in relatively high rainfall areas in humid locations.

System

There are nine genera with about 600 species. The family is monophyletic. It splits into two major clades, the Trichomanoiden and Hymenophylloiden, corresponding to the two largest genera in about.

Smith et al. (2006) summarize all genres of hymenophylloiden clade to the genus Hymenophyllum because the classic genres in pedigrees come to lie within the genus or even are not monophyletic. Trichomanes S. L. consists of eight monophyletic genera.

The genera of Hautfarngewächse are:

• Abrodictyum C. Presl, with about two ways.
• Callistopteris Copel. , With about five species between Malaysia's and the western Pacific.
• Cephalomanes C. Presl, with about 12 species.
• Crepidomanes (C. Presl ) C. Presl, with at least 28 species.
• Didymoglossum Desv. , With at least nine species.
• Skin ferns ( Hymenophyllum Sm ), with about 130 species, including outside Europe the species: Hymenophyllum demissum ( G. Forst. ) Sw. & Schrad, home. Zealand.
• Hymenophyllum hirsutum (L.) Sw, home. Tropics.
• Hymenophyllum polyanthon ( Sw. ) Sw, home. Tropics.

• Polyphlebium ulcers ( R. Br ) Copel.

• Trichomanes reniforme G. Forst, home. Zealand.
• Trichomanes scandens L., Origin: Mexico and the West Indies.

Skin Ferns in Central Europe

• The English Hautfarn ( Hymenophyllum tunbrigense ) comes in the British Isles, in Alsace, Luxembourg ( Luxembourg's Little Switzerland ), formerly also in the Elbe Sandstone Mountains and in Bollendorf (disputed, see web link on the history of Hymenophyllum ).

• The Magnificent Dünnfarn ( Trichomanes speciosum, Willd. ) Is actually rather atlantic widespread species that occurs only as a relatively inconspicuous algae -like gametophyte in Germany. This gametophytic prothallia grow in very low light, deep, moist columns of rocks of acidic, siliceous rock. Proved he is, for example, the Southshore mountain country and the Eifel. Sites in southern Lower Saxony represent the currently most north-eastern occurrences of the gametophytes of Trichomanes speciosum in Europe. It is available, inter alia, also in Luxembourg.

In Austria the skin ferns do not occur.