TAXONOMY OF HOYA LYI, HOYA YUENNANENSIS AND HOYA MEKONGENSIS (APOCYNACEAE – ASCLEPIADOIDEAE)

Hoya lyi H.Lév. and H. yuennanensis Hand.-Mazz. (Apocynaceae – Asclepiadoideae), described at the beginning of the 20th century from specimens collected in South West China, have often been confused with each other and with H. carnosa R.Br. Currently Hoya yuennanensis is considered a synonym of H. lyi but after the selection of lectotypes and the comparison of extensive herbarium materials from the region two species are once again recognised. Emended descriptions and illustrations are provided. The recently described Hoya mekongensis M.G.Gilbert & P.T.Li is synonymised with H. yuennanensis.