19a. Argyreia osyrensis var. osyrensis
聚花白鹤藤 (原变种) ju hua bai he teng (yuan bian zhong)
Ipomoea osyrensis Roth, Nov. Pl. Sp. 117. 1821; Argyreia aggregata (Roxburgh) Choisy; Lettsomia aggregata Roxburgh; Lettsomia aggregata var. osyrensis (Roth) C. B. Clarke.
Leaf blade densely gray tomentose or woolly abaxially, sparsely strigose-villous adaxially, hairs with distinct swollen bases. Fl. Aug, fr. Dec.
Forests, thickets; near sea level. Hainan [?Bangladesh, ?Cambodia, India, Indonesia, Laos, ?Malaysia, Myanmar, Sri Lanka, Thailand, Vietnam]
Specimens from the Deccan region in India have adaxially glabrous leaves, whereas those from east Asia, including China, are uniformly sparse hairy adaxially.