Psilotopsida
| Psilotopsida | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Psilotum nudum |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Psilotopsida | ||||||||||||
| DH Scott |
common adder's tongue ( Ophioglossum vulgatum )
The class Psilotopsida comprises two rather dissimilar plant families, the fork leaf family and the adder tongue family .
features
The relationship between the two families was only clarified in recent years using molecular biological methods, since both families have simplified morphological structures.
The reduction of the root system is a common feature; the fork-leaf family has no roots at all. The gametophytes live underground, are not photosynthetically active and have a mycorrhiza . The sporangia sit adaxially (towards the shoot axis), and they develop eusporangiat (the sporangia wall has several cell layers).
Systematics
The fork-leaf-like are the sister group of all other ferns . No fossils are known of the fork-leaf family, the adder-tongue family has only been known to be fossilized since the late Paleocene ( Botrychium wightonii ). There are only around 100 species in six genera.
- Order adder tongue-like (Ophioglossales)
- Family adder tongue plants (Ophioglossaceae) with around 80 species in four genera
- Order fork-like (Psilotales)
- Fork leaf family (Psilotaceae) with 12 species in two genera
literature
- 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 .
- Kathleen M. Pryer, Eric Schuettpelz, Paul G. Wolf, Harald Schneider, Alan R. Smith, Raymond Cranfill: Phylogeny and evolution of ferns (Monilophytes) with a focus on the early leptosporangiate divergences. In: American Journal of Botany. Volume 91, No. 10, 2004, pp. 1582-1598, DOI: 10.3732 / ajb.91.10.1582 .
