Rediscovered Phylogenetics of Wenchengia (Lamiaceae)

Wenchengia C. Y. Wu & S. Chow, a rare and endangered monotypic genus of Lamiaceae, is endemic to the island of Hainan. The genus and its sole member species, W. alternifolia C. Y. Wu & S. Chow was established on the basis of two collections (four sheets) from the 1930s. The genus is characterized by alternate leaves, racemose inflorescences, and a unique type of nutlet attachment described as vascular funicles and slender stalks, and was assigned to a monotypic subfamily, Wenchengioideae, based on its morphological uniqueness in Lamiaceae. However, the phylogenetic positionof the genus has long been controversial. It variously has been supported as sister group of subfamily Ajugoideae, treated as a member of Scutellarioideae, or suggested to be related to Lamioideae.

Therefore, Prof. ZHANG Dianxiang in Plant Phylogenetics and Reproductive Biology Research Group of South China Botanical Garden choosed the topic as the main doctoral research of one of his Ph.D candidates, LI Bo. Following several times field expeditions, Bo Li et al. rediscovered a single population of about 40 living plants of W. alternifolia on Hainan Island, that makes it possible to reevaluate the phylogenetic position of Wenchengia using evidence from molecular as well as more morphological, anatomical, and cytological data.

Both the molecular data and a combination of the molecular and the morphological data suggested a close relationship of the genus to a clade consisting of Holmskioldia, Tinnea, and Scutellaria representing subfamily Scutellarioideae. This relationship is also supported by a striking similarity in gross morphological, anatomical and cytological characters between Wenchengia and other genera of Scutellarioideae, suggesting that it should be more appropriate to treat the genus as a member of the Scutellarioideae, rather than assigning it to a monotypic subfamily.

Some Lamiaceae experts from Florida International University, Ohio University, University of Washington, Kunming Institute of Botany (CAS), Nanjing University are co-authors of the study.

Now, the research results are published in Taxon 61（2）：April 2012: 392–401. http://chinesesites.library.ingentaconnect.com/content/iapt/tax/2012/00000061/00000002/art00010

W. alternifolia C. Y. Wu & S. Chow