APPLEQUIST, WENDY L.* AND ROBERT S. WALLACE. Department of Botany, Iowa State University, Ames, IA 50011. - Molecular systematic appraisal of Tribe Anacampseroteae (Portulacaceae).
The type genus of the tribe Anacampseroteae Nyananyo ex Rowley
(Portulacaceae) is Anacampseros L., comprising (as usually
circumscribed) about 25 species of small xerophytic plants possessing
a distinctive fruit with deciduous exocarp. Subg. Tuberosae
contains two species; Subg. Anacampseros, exclusively African,
is divided into Sect. Avonia, which has tiny leaves concealed
by stipular scales, and Sect. Anacampseros, with fleshy leaves.
Previous researchers have suggested that Anacampseros and the
small or monotypic genera Grahamia, Talinaria, Talinopsis and
Xenia, the remaining members of the tribe, form a monophyletic
group. Gerbaulet (1992) produced a detailed cladogram based on
morphological data. Her classification, summarized above, has been
disputed by Rowley (1994), who segregates Sects. Anacampseros
and Avonia into separate genera and combines all remaining
species within the tribe into Grahamia. Hershkovitz and
Zimmer's (1997) ITS study of the Portulacaceae suggested relationships
among these lineages different from those proposed by either Gerbaulet
or Rowley. The intent of the present study is to provide additional
phylogenetic information based on plastid sequences, which can be
compared to other researchers' cladograms from different data sets.
Implications for classification and nomenclature will be examined.
Key words: Anacampseros, cpDNA, Portulacaceae