A revision of Calvoa Hook. f. (Melastomataceae)

Abstract

A revision of the genus Calvoa Hook. f. (Melastomataceae) is presented. Principal Component Analyses (PCA) and Cluster Analyses (UPGMA) were performed to elucidate three cases of difficult species delimitation and infraspecific variation, with the following results. (1) The separation between C. crassinoda Hook. f. and C. grandifolia Cogn. was clear in the results obtained with both methods. (2) The group of the West-Central African speciesCalvoa angolensis A. Fern. & R. Fern C. calliantha Jacq.-Fél C. monticola A. Chev C. pulcherrima Gilg ex Engl C. sapinii De Wild C. seretii De Wild C. sinuata Hook. f. and C. subquinquenervia De Wild. proved difficult to resolve with either analysis, but the Cluster Analysis produced results which are more consistent with the identification of the specimens. (3) Neither of the two analyses supported the recognition of infraspecific categories in Calvoa orientalis Taub. Eighteen species are recognized in the genus. The new speciesCalvoa jacques-felixii E. Figueiredo is described and the new combination Calvoa seretii subsp.wildemaniana (Exell) E. Figueiredo is made. Four lectotypes are designated. The conservation status of some taxa is discussed. Six species are considered rare and possibly under threat.