VON BALTHAZAR, MARIA*, YIN-LONG QIU, AND PETER K. ENDRESS. University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland. - Phylogenetic relationships and character evolution in Buxaceae.
Buxaceae are a small eudicot family of mostly monoecious evergreen
shrubs and comprise up to five genera (Buxus, Notobuxus,
Sarcococca, Pachysandra, Styloceras) and 120
species. Delimination of the family and inter- and intrageneric
relationships within the family have been controversial. Sequences of
nuclear ITS and plastid ndhF from 25 representatives of
Buxaceae were analyzed separately and in combination to resolve
phylogenetic relationships among and within genera. Two major clades
were identified: the clade of Pachysandra, Sarcococca,
and Styloceras and the clade of Buxus
andNotobuxus. Pachysandra and Sarcococca were two
strongly supported monophyletic groups. The sister relationship of
Sarcococca to the clade of Pachysandra and
Styloceras is also strongly supported. American and Eurasian
Buxus each form a strongly supported clade. The controversial
genus Notobuxus is embedded among African members of
Buxus. Ongoing morphological studies will improve our
understanding of the evolution of morphological characters and
phylogenetic relationships of Buxaceae.
Key words: Buxaceae, character evolution, ITS, molecular phylogeny, ndhF