The Bryoxiphiaceae is a small family of mosses composed of one genus, Bryoxiphium, accommodating 2 to 5 taxa. The gametophyte of Bryoxiphium resembles somewhat that of Fissidens, and it is based on this similarity that the family has traditionally been placed within the haplolepideous mosses. A peristome, upon whose features the classification of mosses rests to a large extant, is, however, lacking. Recent phylogenetic reconstructions of mosses using nucleotide sequences of the nuclear and chloroplast genome, lead to Bryoxiphium being placed in a clade with Drummondia and Scouleria, at the base of either the haplolepideous mosses (Dicranideae) or diplolepideous opposite mosses (Funariideae.). We have tested these relationships, as well as affinities to Eustichia, by sampling all species of Bryoxiphium; results of these analyses will be represented. Species of Bryoxiphium are morphologically distinct, and geographically allopatric. Bryoxiphium norvegicum is the most widely distributed species, extending from Eastern Greenland and Iceland to Western North America. B. japonicum, B. mexicanum, and B. madeirense, are endemic to Eastern Asia, Mexico and the island of Madeira, respectively. Whether these morphological species compose monophyletic lineages is not clear. The relationships among these taxa are examined using nucleotide sequences of the ITS region of the rDNA and the chloroplast regions trnL-trnF and rps4 gene based on an extensive sampling of populations.

Key words: Bryoxiphiaceae, Bryoxiphium, ITS, rps4, trnL-trnF