SIMMONS, MARK PITKIN*, VINCENT SAVOLAINEN, CURTIS C. CLEVINGER, ROBERT H. ARCHER, AND JERROLD I. DAVIS. L.H. Bailey Hortorium, Cornell University, Ithaca, NY 14853; Jodrell Laboratory, Molecular Systematics Section, Royal Botanic Gardens, Kew, Richmond Surrey TW9 3DS, United Kingdom; Department of Botany, University of Texas, Austin, Texas 78713; National Herbarium, National Botanical Institute, Private Bag X101, Pretoria 0001, Republic of South Africa. - Phylogeny of the Celastraceae inferred from morphology and nuclear and plastid loci.
Phylogenetic relationships within the Celastraceae were inferred from
a simultaneous analysis of morphological characters and sequence-based
characters from the 5' end of 26S nuclear ribosomal DNA, the first
exon of phytochrome B, rbcL, and atpB. Two genera
previously assigned to the Celastraceae, Forsellesia and
Goupia, are resolved as members of the Crossosomataceae and the
Goupiaceae, respectively. Lepuropetalon and Parnassia
(Saxifragaceae) are resolved as members of an early-derived lineage
within the Celastraceae. The Stackhousiaceae are resolved as a
monophyletic group nested within the Celastraceae. Canotia is
supported as the sister group of Acanthothamnus within the
Celastraceae. Maytenus sensu lato is resolved as a
polyphyletic assemblage with Gymnosporia and Tricerma
derived from different lineages. Maytenus sensu stricto
remains an unnatural genus that needs to be re-circumscribed.
Cassine sensu stricto, endemic to South Africa, is supported as
distinct from the large, widely-distributed genus Elaeodendron.
Kokoona and Lophopetalum are resolved as
"transitional genera" between the Celastraceae sensu stricto
and the Hippocrateaceae. Plagiopteron (Plagiopteraceae) is
supported as closely related to Hippocratea sensu lato. The
Hippocrateaceae (including Plagiopteron and
Lophopetalum) are supported as a monophyletic group nested
within the Celastraceae. The classifications of the Celastraceae
sensu stricto and the Hippocrateaceae by Loesener and Hallé,
respectively, are not supported. Arils appear to have two independent
origins within the Celastraceae and have been variously modified into
mucilagenous pulp, seed wings, or lost.
Key words: 26S nuclear ribosomal DNA, Celastraceae, Celastrales, Hippocrateaceae, phytochrome B, Stackhousiaceae