Description from Flora of China
Otostemma lacunosum (Blume) Blume.
Subshrubs epiphytic. Stems climbing to 1.5 m by adventitious roots, glabrous or sparsely pubescent. Petiole 3-12 mm, subglabrous; leaf blade ovate or ovate-lanceolate, 2-5 × 1.2-3 cm, glabrous or subglabrous, base cuneate or rounded, apex acute; lateral veins 2-4 pairs, obscure. Peduncle 2.5-7 cm, robust. Pedicel 5-13 mm. Sepals obtuse. Corolla white with violet dots, 6-7 mm in diam., tube conspicuously white villous inside; lobes suborbicular, much longer than tube. Corona lobes ovate, constricted at middle, outer angle rounded, inner angle acute, surface with a thin keel. Apical anther membranes triangular, exceeding stigma head; pollinia subobovate. Follicles lanceolate, 5-7 cm.
Decoctions of all parts are used to detoxify insect bites, draw out pus, and reduce swellings.
Cultivated in S Guangdong [introduced from Indonesia]