Perennial, dense, evergreen shrub, 1-1.5 m high, sometimes arborescent reaching about 5-6 m tall; stem terete, glabrous; leaves opposite, ovate, elliptic or lanceolate, acuminate or acute at apex, tapering towards base, entire, minutely pubescent when young, lateral nerves 8-12 pairs; petioles 2-3 cm long; flowers in dense, axillary spikes, 2-12 cm long; bracts leafy, elliptic, subacute, glabrous or nearly so, 5-7 nerved, bracteoles fulcate-oblong, single nerved, margins ciliate; calyx deeply 5-lobed, sepals-5, equal, oblong-lanceolate, acute, 3 nerved, glabrous or slightly pubescent; corolla large, white, 2-lipped, tube short, wide, upper lip curved, notched at apex, lower lip white with palate transeversely rose barred or dotted in the throat; stamens-2, adnate to top of corolla tube, exserted, anthers 2-celled, minutely apiculate at base; staminodes absent; disk cupular; ovary 2-locular, 2-ovules in each cell, usually hairy, style filiform, stigma globose' capsule clavate, pubescent, 4-seeded; seeds globose, glabrous, tuberculate, dark brown.