''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 ...

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. 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 A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...

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 Johann Hedwig (8 December 1730 – 18 February 1799), also styled as Johannes Hedwig, was a German botanist notable for his studies of mosses. He is sometimes called the "father of bryology". He is known for his particular observations of sexual r ...

in 1801, with the name being derived from the Greek word for moss. Botanist

John R. Spence John is a common English name and surname: * John (given name) * John (surname) John may also refer to: New Testament Works * Gospel of John, a title often shortened to John * First Epistle of John, often shortened to 1 John * Second ...

published a reclassification of the genus in 2005. The genus '' Ptychostomum'' 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