Heterostemma pingtaoi S. Y. He & J. Y. Lin (Apocynaceae, Asclepiadoideae) is described from Hainan Province, China. The new species is morphologically similar to H. oblongifolium Costantin in its leaf blade with an acute apex and rounded base. In comparison, H. pingtaoi differs from H. oblongifolium in its pubescent petioles (vs. glabrous), the leaves only to 7.3 cm long (vs. 7.5–14 cm), the five calyx glands (vs. 10), and the corolla externally
pubescent and yellow-green with mauve pubescence (vs. green and glabrous).
Key words: Apocynaceae, Asclepiadoideae, China, Hainan, Heterostemma, IUCN Red List.
Heterostemma pingtaoi (Apocynaceae, Asclepiadoideae), a New Species from Hainan, China