Ricciaceae
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The Ricciaceae are a family of liverworts and are there in the order Ricciales .
features
The thallus has air cavities, but usually no air openings. The thallus is forked and usually grows rosette-shaped. The assimilation tissue consists of pillar-like cell cords. These end up in a large nipple-like cell. The basic tissue is made up of uniform cells of the same type. The lower layer is free of chlorophyll . The oil cells that are otherwise typical of thaleless liverworts are missing or only present in Ricciocarpos .
The sexual organs ( gamentangia ) are sunk into the thallus. They open outwards so that fertilization can take place through a film of water on the surface of the thallus. The sporogon also remains in the thallus, since it has neither a foot nor a stem ( seta ). The spores are only released when the dead thallus disintegrates. Elaters are absent.
Systematics
The family contains only two genera:
- Ricciocarpos is monotypical with the only species Ricciocarpos natans that swims freely on the surface of eutrophic waters.
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Riccia with over 150 species.
- Riccia fluitans
- Blue-green star liver moss ( Riccia glauca )
- Riccia melitensis
Sister taxon of the Ricciaceae is the monotypic family Oxymitraceae .
literature
- Jan-Peter Frahm: Biology of Mosses . Spektrum Akademischer Verlag, Heidelberg and Berlin 2001, p. 41f. ISBN 3-8274-0164-X
- Jan-Peter Frahm, Wolfgang Frey, J. Döring: Moosflora . 4th, revised and expanded edition (UTB for Science, Volume 1250). Ulmer, Stuttgart 2004, ISBN 3-8001-2772-5 (Ulmer) & ISBN 3-8252-1250-5 (UTB)
Web links
Individual evidence
- ↑ a b Wolfgang Frey, Eberhard Fischer, Michael Stech: Bryophytes and seedless Vascular Plants . In: Wolfgang Frey (Ed.): Syllabus of Plant Families - A. Engler's Syllabus of Plant Families . 13th edition. tape 3 . Borntraeger, Berlin / Stuttgart 2009, ISBN 978-3-443-01063-8 , pp. 34-35 .