Revival of Murtonia (Leguminosae Tribe Desmodieae)

Abstract

The systematic position of Desmodium craibii H. Ohashi (Leguminosae/Fabaceae), originally described as Murtonia kerrii Craib endemic to Thailand, has been problematic. To solve the problem, the chloroplast DNA and nuclear DNA of the species were examined by phylogenetic methods. New and robust phylogenetic trees of tribe Desmodieae are presented incorporating the DNA data of D. craibii. The species forms a distinct clade among the genera of tribe Desmodieae in the phylogenetic trees. The clade is sister to the clade composed of Desmodiopsis-Oxytes subclade and Desmodium subclade in the cpDNA tree. In the nrDNA tree it forms a separate clade with the Daprainia kingiana clade, which is sister to the clade consisted of the Desmodiopsis-Oxytes subclade and Desmodium subclade. Desmodium craibii is, therefore, returned to Murtonia, as M. kerrii Craib. The genus is supported morphologically in having small lateral branches at the axils of leaves bearing an inflorescence and stipular bracts with scales at nodes on inflorescence axis.