''Bryum'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
moss
Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...
es in the family
Bryaceae
Bryaceae is a family of mosses.
Genera
Genera include:Buck, William R. & Bernard Goffinet. 2000. "Morphology and classification of mosses", pages 71-123 ''in'' A. Jonathan Shaw & Bernard Goffinet (Eds.), ''Bryophyte Biology''. (Cambridge: Cambri ...
. It was considered the largest genus of mosses, in terms of the number of species (over 1000), until it was split into three separate genera in a 2005 publication.
[New genera and combinations in Bryaceae (Bryales, Musci) for North America, J. R. Spence, Phytologia 87: 15-28 (2005)]
/ref> As of 2013, the classification of both ''Bryum'' and the family Bryaceae to which it belongs underwent significant changes based on DNA studies.[Genus ''Bryum'', California Moss eFlora, Jepson eFlora for CA Vascular Plants, University Herbarium, University of California]
/ref>
Description
''Bryum'' is a polyphyletic genus that has high morphological variation. Bryum species generally have shorter laminal cells with short, thick, and rounded stems.[ All ''Bryum'' species exhibit narrowed cells at the margins. Bryum species can be identified through patterns of ]asexual reproduction
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the fu ...
, coloration features of the stem and leaf base, and the strength of the leaf border.[
]
History
The genus was described by Johann Hedwig in 1801, with the name being derived from the Greek word for moss.
Botanist John R. Spence published a reclassification of the genus in 2005. The genus ''Ptychostomum
''Ptychostomum'' is a genus of mosses belonging to the family Bryaceae. It has an almost cosmopolitan distribution
In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world i ...
'' was reinstated, while the genera '' Leptostomopsis'', and '' Plagiobryoides'' were created.[ The genera '' Gemmabryum'', '' Imbribryum'', and '' Rosulabryum'' were later published to further divide ''Bryum''.]
References
{{Authority control
Moss genera