THE PHYLOGENY AND CLASSIFICATION OF MNIACEAE AND RHIZOGONIACEAE (MUSCI)

Abstract

  A cladistic analysis of the genus Mnium Hedw. and related taxa suggests that Mnium s. str. is more closely related to the genera of the Rhizogoniaceae than to most of the other genera of the traditional Mniaceae. In the new classification the Mniaceae contains the genera Mnium, Leucolepis Lindb., Trachycystis Lindb., Pyrrhobryum Mitt., Cryptopodium Brid., Hymenodontopsis Hertz. and Leptotheca Schwaegr. and the Rhizogoniaceae contains the genera Rhizogonium Brid., Hymenodon Hook. f. & Wils., Mesochaete Lindb. and Goniobryum Lindb. The new family, Plagiomniaceae, comprizing the earlier Mniaceous genera Plagiomnium T. Kop., Orthomnion Wils. and Pseudobryum (Kindb.) T. Kop. is described. The placement of the earlier Mniaceous genera Cinclidium Sw., Cyrtomnium Holmen and Rhizomnium T. Kop. remains uncertain, and they are tentatively placed in the family Cinclidiaceae Kindb. Most of the genera of the Mniaceae in its new limitation occur in South America-Australasia and possibly are Gondwanalandic. Mnium s. str. is Laurasian and Leucolepis is a Pacific Coast endemic to North America. Only one pantropical autoicous species of Pyrrhobryum is present in tropical Africa. Rhizogoniaceae s.str. is Gondwanalandic, and the Cinclidiaceae and Plagiomniaceae are Laurasian.