OLMSTEAD, RICHARD G.*, PHILIP D. CANTINO, BRENDAN LEPSCHI, AND PATRICK A. REEVES. Department of Botany, University of Washington, Seattle, WA 98195 USA, Dept. Environmental & Plant Biology, Ohio University, Athens, OH 45701 USA, Australian National Herbarium, GPO Box 1600, Canberra, ACT, 2601, Australia, Department of Botany, University of Washington, Seattle, WA 98195 USA. - A molecular systematic study of the Prostantheroideae (Lamiaceae), including Chloantheae (formerly Verbenaceae).
As part of our ongoing molecular systematic research into the
phylogeny of the Lamiales, we have conducted an investigation of the
hypothesis put forward by Cantino that the Australian endemic labiate
tribe Westringieae (= Prostanthereae) and the Australian endemic
verbenaceous tribe Chloantheae together form a monophyletic group,
which also included Tectona (Verbenaceae/Viticoideae sensu Briquet).
The evidence for this postulated relationship comes from a cladistic
analysis of morphological and anatomical characters, in which members
of these two groups come out adjacent to each other in an unrooted
tree. A total of 58 sequences was analysed, including the 24
sequences representing Chloantheae and Westringieae, along with 33
sequences representing species from throughout the Lamiaceae
(including Spartothamnella) and related families. The results
provide strong support for monophyletic groups comprising Chloantheae,
Westringieae, and those two clades combined (Prostantheroideae).
Tectona is not found to belong to this group.
Spartothamnella is found to not belong with the
Prostantheroideae, but belongs in Teucrioideae. It is sister to
another Australian endemic, Oncinocalyx, and together they are
sister to the New Zealand endemic Teucridium. These three
taxa, all formerly assigned to Verbenaceae, are most closely related
to Teucrium, traditionally assigned to Lamiaceae.
Key words: Chloanthoideae, Lamiaceae, Prostanthereae, Verbenaceae