Pearl fern family
| Pearl fern family | ||||||||||||
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Pearl fern ( Onoclea sensibilis ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Onocleaceae | ||||||||||||
| Pic.Serm. |
The pearl fern family (Onocleaceae) are a family of the spotted ferns (Polypodiales) within the real ferns (Polypodiopsida).
features
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The rhizomes are long to short creeping to ascending, sometimes they form runners ( Matteuccia , Onocleopsis ). The leaves are distinctly dimorphic : the fertile ones are designed much differently than the sterile ones. The petiole has two vascular bundles that unite distally to form a trough-shaped one. The leaf blades are pinnate to pinnate. The nerves terminate freely or are anastomosing . The spores are kidney-shaped, brown to green. The sori are enclosed by the rolled up leaf edges. Sometimes there are also real Indusia .
The basic chromosome number is x = 37 for Onoclea and 39 or 40 for the other genera.
distribution
The family occurs predominantly in the northern temperate areas and grows terrestrially .
Systematics
The Onocleaceae family is monophyletic . Their sister taxons are the Blechnaceae .
The Onocleaceae family, according to Smith et al. 2006 four genera with a total of only about eight species:
- Ostrich ferns ( Matteuccia Tod. ): The only three or so species occur in the temperate zones of the northern hemisphere.
- Pearl fern ( Onoclea L. ): The only four or so species occur in the temperate zones of the northern hemisphere.
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Onocleopsis F. Ballard : It contains only one species:
- Onocleopsis hintonii F. Ballard : It is distributed from Mexico to Central America.
- Pentarhizidium Hayata (the species are also partly assigned to Matteuccia , partly to Onoclea ).
supporting documents
- Alan R. Smith, Kathleen M. Pryer, Eric Schuettpelz, Petra Korall, Harald Schneider, Paul G. Wolf: A classification for extant ferns. In: Taxon. Volume 55, No. 3, 2006, ISSN 0040-0262 , pp. 705-731, abstract, PDF file .
- David John Mabberley: The Plant Book. A portable dictionary of the higher plants . Cambridge University Press, Cambridge et al. 1987, ISBN 0-521-34060-8 .
