Polystichum
Bristlecone shield fern ( Polystichum setiferum )
The shield ferns ( Polystichum ) are a cosmopolitan fern genus that includes about 200 to 300 species. It took its name from the shield-shaped indusia.
Description
It is continuous around soil inhabiting ferns, whose main shoots grow erect to ascending. All species are evergreen.
The fertile and sterile fronds are alike (except Polystichum acrostichoides ). They are in shape to linear- lanceolate to broadly lanceolate, pinnate and one to three times. In many species, the leaf blade is a little pudgy to thick - leathery. The top Fiederabschnitte have an asymmetric base with a forwardly directed tooth at the many species. The main axis of the frond is often busy with chaff shed.
The sori are located on each Fiederabschnitt in one row between the two leaf margins and midrib. They are round and are covered by a rounded, shield-shaped indusium, which falls very early in some species, while others can also stay long.
System
The genus was originally used as a " collective species", in which many species have been incorporated with uncertain or unclear status of family relationships. It is expected that many species arrive sometime in other existing or new genres.
The fact that the species of the genus often form hybrids, and the great morphological similarity, in particular the multi- feathered species, also make a Artabgrenzung difficult. Since a revision of the genus pending so far are probably some of the existing species names synonyms, others will probably end up more as subspecies of a single species.
Distribution and habitat requirements
The genus has a worldwide distribution of the polar regions to the tropics.
Most species grow on the forest floor, or on earth or in crevices in rocky slopes.
Types (selection)
Of the 180 to 300 species are following in Europe, North Africa and the Middle East before:
- Lobed shield fern, Glanzschildfarn or Thorny shield fern ( Polystichum aculeatum (L.) Roth), a typical type air moist slope forests
- Tender shield fern shield fern or Brauns ( Polystichum braunii ( Spenner ) Fée ), characteristic species of calcium deficiency ravine forests ( Fraxino - Aceretum pseudoplatani )
- Polystichum Drepanum ( Sw. ) C.Presl, occurs only in Madeira.
- Polystichum falcinellum ( Sw. ) C.Presl, also only in Madeira.
- Lance shield fern ( Polystichum lonchitis (L.) Roth ), a type of scree slopes of the high mountains, and the only European with pinnate leaves.
- Bristlecone shield fern shield fern or bristly ( Polystichum setiferum ( Forssk. ) Moore ex Woynar ), a more common way south humid air mixed beech forests, which occurs at a few growing sites in Germany. It is often planted in gardens.
- Polystichum webbianum ( A.Br. ) C.Chr. , Only on Madeira.
- Polystichum woronowii Fomin, whose distribution area begins only in Eastern Europe.
In addition, one finds from time to time, the hybrids
- Polystichum × bicknellii (Christ ) Hahne ( = Polystichum Polystichum × aculeatum setiferum )
In Germany, all shield fern species are protected.
As ornamental plants play except the mentioned Thorny shield fern, the following types a role:
- Dolchfarn or Weihnachtsfarn ( Polystichum acrostichoides ( Michx. ) Schott), a North American species (Canada, USA, Mexico), which propagates slowly with an ascending rhizome
- Anderson's shield fern ( Polystichum andersonii Hopkins ), Origin: Canada, Alaska, United States
- Polystichum auriculatum (L. ) C. Presl, Origin: India, Sri Lanka
- Polystichum lepidocaulon ( Hook. ) J. Sm, Origin: China, Korea, Japan, Taiwan
- Polystichum makinoi ( Tagawa ) Tagawa, Origin: Japan
- Polystichum mohrioides ( Bory ) C. Presl, Origin: British Columbia, Western USA
- Sword Fern ( Polystichum munitum ( Kaulf. ) C. Presl ), Origin: Canada, USA, Mexico, is occasionally naturalized in Europe
- Polystichum neolobatum Nakai, Origin: India, China, Japan, Taiwan
- Polystichum neozelandicum Fée, Syn Polystichum richardii from New Zealand and Oceania
- Japanese shield fern ( Polystichum polyblepharum ( Rom. ) C. Presl ), Origin: Japan and South Korea
- Polystichum proliferum ( R.Br. ) C.Presl from Australia
- Polystichum retrorsopaleaceum ( Kodama ) Tagawa from Japan
- Polystichum rigens Tagawa, Origin: Japan
- Polystichum tripteron ( Kunze ) C. Presl, Origin: Eastern Siberia, China, Japan
- Polystichum tsus - simense ( Hook. ) J. Sm, Origin: China, Korea, Japan, Taiwan
The species Polystichum fuentesii Espinosa from Easter Island is known only from a collection from 1911 and is considered extinct.