The Phylogeny of Leucothoë s. l. (Ericaceae: Vaccinioideae) based on Morphological and Molecular (ndhF, matK, and nrITS) Data

Leucothoë s. l. has been split into as many as three genera in current taxonomic work involving morphological data. In this paper, phylogenetic relationships within Leucothoë s. l. were examined using DNA sequence data from matK, ndhF, nrITS, and morphological characters. The total combined data indicate that Leucothoë s. l. species are distributed between two clades. Leucothoë racemosa and L. recurva are strongly supported as being sister taxa and are in turn sister to Chamaedaphne calyculata. These two Leucothoë species are deciduous and they exhibit “L. racemosa”-type autumn inflorescences (as does Chamaedaphne). The other six Leucothoë s. l. species (L. axillaris, L. davisiae, L. fontanesiana, L. grayana, L. griffithiana, and L. keiskei) form a strongly supported clade. Leucothoë grayana, a morphologically distinctive taxon, is sister to the other five species in this latter clade. Based on these data, it is proposed that Leucothoë s. l. should be divided into three genera: Eubotryoides (E. grayana), Eubotrys (E. racemosa and E. recurva), and Leucothoë s. s. (L. axillaris, L. davisiae, L. fontanesiana, L. griffithiana, and L. keiskei).