An evergreen climber at least 15 ft high, of dense, much branched habit; the young shoots very hairy, and the hairs persisting for several years, but almost glabrous in some forms. Leaves leathery, opposite, oval or slightly ovate, 3⁄4 to 2 in. long, 3⁄8 to 3⁄4 in. wide, mostly blunt at the apex, dark glossy green, glabrous; stalk 1⁄8 in. or less long. Flowers yellowish white, fragrant, produced in July and August in slender terminal cymes 2 to 21⁄2 in. long. Calyx-lobes erect, narrow, pointed, not reaching to the top of the narrow basal part of the corolla-tube. Corolla with a tube about 3⁄8 in. long, and with five spreading obovate lobes, giving it a diameter of 3⁄4 in.; lower part of corolla-tube narrow, and about twice as long as the widened upper part. Stamens inserted on the upper part of the tube and slightly protruding.
Native of Japan and of southern and central Korea. All the plants originally grown in gardens derived from one which had grown for many years on a garden wall at Kew, where it was hardy and flowered with great profusion in some years. But there have probably been other introductions since then, some perhaps less hardy. The Kew plant was originally considered to represent a distinct species, named T. crocostomum by Stapf, and it has been suggested that matching plants occur in China. But recent works include it in T. asiaticum, and it is probable that the plant came from Japan or Korea.
T. asiaticum has smaller leaves and yellower flowers than T. jasminoides, and is readily distinguished when in flower by the erect calyx-lobes, which in T. jasminoides are larger and distinctly turned back.
T. gracilipes Hook. f. – T. divaricatum var. brevisepalum Schneid., in part – Allied to T. asiaticum but the calyx minute and the inflorescences on usually longer peduncles. Native of N.E. India, S. China, Formosa and the former Indochina. Not known to be in cultivation.