The bryophyta (mosses): Systematic and evolutionary inferences from an rps4 gene (cpDNA) phylogeny

Phylogenetic analyses of nucleotide and amino acid sequences of the chlorop last protein coding gene rps4 were performed for 225 species of mosses, rep resenting 84 % of families recognized by Vitt (1984. In: Schuster RM, ed. N ew manual of bryology, vol 2. Nichinan: Hattori Botanical Laboratory), unde r the criterion of maximum parsimony with Takakia and Sphagnum as outgroups . Most parsimonious topologies converge to a scenario wherein the Andreaeid ae are monophyletic and sister to the Bryidae (peristomate mosses), the Nem atodonteae and the Buxbaumiaceae form a monophyletic lineage, the Diphyscia ceae are sister to the Arthrodonteae and, within the latter, the Funarineae -Encalyptineae-Timmiaceae-Haplolepideae compose a monophyletic clade sister to remaining diplolepideous mosses. This hypothesis suggests that early in the evolution of the Arthrodonteae, two major lineages diverged, with oppo site and alternate peristomes, respectively. Bootstrap support for the deep dichotomies is poor or lacking but increases when protein translations of rps4 sequences are included in the analysis. Several novel systematic hypot heses are raised, including (a) a diplolepideous rather than haplolepideous origin of the Pleurophascaceae; (b) an affinity of the Catascopiaceae with the Funariineae rather than the Bryineae; and (c) a close relationship of the Calomniaceae and Mitteniaceae to the Rhizgoniaceae. The advantages and disadvantages of a single gene phylogeny are discussed with respect to the identification of polyphyletic familial or suprafamilial taxa. (C) 2001 Ann als of Botany Company.