COX, CYMON J.* AND TERRY A. J. HEDDERSON. Department of Botany, Duke University, Durham, NC 27708, USA and, Department of Botany, University of Cape Town, Private Bag, Rondebosch 7701, South Africa. - Molecular phylogenetic analyses of the Bryaceae (Bryales, Musci).
Phylogenetic relationships among the traditional taxa of the Bryaceae
have been highly contentious due to uncertainty associated with
homology assessment of morphological characters within the family. In
particular, the reliance on sporophytic characters for the
delimitation of genera has been questioned. Previous analyses based on
molecular data have provided insights into the evolution of the group
and established a framework for classification. Following these
analyses, the Bryaceae has recently been recircumscribed to include
only those members of the traditional sub-family Bryoideae (except
Leptobryum), namely, the genera Acidodontium,
Anomobryum, Brachymenium, Bryum,
Plagiobryum, and Rhodobryum. Here we present analyses
based on chloroplast DNA sequences (rps4 and trnL-trnF) to evaluate
phylogenetic relationships within the recircumscribed family. The
deepest division within the Bryaceae resolves a clade containing
Rhodobryum, Brachymenium section Leptostomopsis, and
Bryum section Capillaria subsection Rosulata as the sister
group to the remaining sections of Bryum, plus
Brachymenium sect. Dicranobryum, Acidodontium,
Anomobryum, and Plagiobryum. Within the latter clade,
section Capillaria, section Leucodontium subsection Calophylloideae,
and section Caespiticia subsection Cernuiformia of Bryum are
resolved with Plagiobryum. Within the sister group to this
clade, section Bryum and Caespiticia subsection Caespiticia of
Bryum form a clade with Brachymenium section
Dicranobryum, Anomobryum is resolved as sister to
Acidodontium, and Bryum sections Limbata and
Apalodictyon subsection Alpiniformia form a clade. These analyses
provide a preliminary basis for the interpretation of natural groups
and morphological evolution in the Bryaceae.
Key words: Bryaceae, Bryum, phylogenetic relationships, rps4, trnL-F