An evergreen shrub (in some of its native habitats a tree 40 to 50 ft high), branchlets warted, otherwise glabrous. Leaves oval, oblong, or somewhat obovate, 3 to 8 in. long, 11⁄2 to 4 in. wide, wedge-shaped or sometimes rounded at the base, slender-pointed at the apex, the terminal half usually remotely toothed, upper surface dark dull green and covered with a thin, waxy layer, which cracks and turns grey when the leaf is rubbed or bent, both surfaces quite glabrous; stalk 1⁄2 to 11⁄2 in. long. Flowers white, quite tubular, about 1⁄5 in. long, produced from July to September in usually seven-rayed cymes 3 to 5 in. across. The cymes are rendered pretty by the protruded bunch of lilac-coloured anthers. Fruits egg-shaped, 1⁄6 in. long, black.
Native of the Himalaya and China; introduced to Kew from India in 1881, and later from Yunnan through the Jardin des Plantes, Paris, in 1892. Most of the plants now in cultivation are Chinese, and these are probably hardier than the Indian ones. They have at any rate succeeded very well. Two characters make this species very distinct, the tubular corolla with erect, not spreading lobes, and the curious waxy covering of the leaves; the latter only shows itself when the leaf is touched or bent; ordinarily they are of a dingy dark green.