Physostelma
(from physa, a bladder, and stelma, a girdle; alluding to the shape of the corona scales). SYN. Cystidianthus. ORD. Asclepiadeae. A genus comprising a couple of species of stove, climbing, glabrous shrubs, natives of the Malayan Archipelago, usually, but erroneously, referred to Hoya. Flowers rather large, in umbelliform cymes; calyx five-parted; corolla very broadly campanulate, sub-cyathiform; corona scales five, fleshy, radiate-patent. Leaves opposite, coriaceous, sub-fleshy, shining, veined. P. Wallichii is the only species in cultivation. For culture, see Hoya.
P. campanulatum (bell-shape-flowered). A synonym of P. Wallichii. P. Wallichii (Dr. Wallich's).* fl. green, yellow; corolla campanulate, glabrous. May. l. coriacesous, almost veinless, oblong, acuminate, glabrous; when dry, reticulately veined. 1845. SYNS. P. campanulatum, Hoya campanulata (B. M. 4545, and B. R. 1847, 54).