A proposed reclassification of Bryum,Anomobryum and Brachymenium (Musci,Bryaceae)

Abstract

The traditional generic classification in the Bryoideae (Bryaceae) is based primarily on details of the sporophyte, particularly peristome reduction and capsule inclination. Recent research, however, has suggested that closely related species in Anomobryum can have very distinct capsules, varying from complete peristomes and inclined capsules to reduced peristomes and erect capsules. The suggestion is made here that sporophyte features, especially those related to peristome features, may obscure phylogenetic relationships. A revised classification is proposed, based on analyses of 100 species of Bryum, Anomobryum, and Brachymenium and sixteen sporophytic and gametophytic characters. The revised classification groups species with similar gametophores but is supported by at least some sporophytic characters. Analysis of variance and principal components analysis indicate that both the traditional and revised classification provide effective summaries of the variation within the 100 species examined. The new classification consists of three informal groups of species which can be recognized at generic rank. One comprises Bryum species, including those with reduced peristomes and inclined capsules. A second comprises all species of Anomobryum, as well as species of Bryum and Brachymenium with similar gametophores. The third group consists of the rosulate species of Bryum and Brachymenium. Phylogenetically, the second group may be more closely related to Pohlia than to the species in the first and third groups. The third group appears to be most closely related to Rhodobryum and Plagiomnium. Suggested names are provided for groups one and three, while the name Bryum is retained for group two. No nomenclatural changes are made, however, until more research is done.