Large straggling shrub or small tree to 9 m tall, often forming a coppice; trunk erect, the bark scabrous; branches numerous, spreading in every direction, short-pubescent; young shoots acutely tetragonal. Leaves decussate-opposite; petioles 5-20 mm long, short-pubescent; leaf blades ovate or those near the flowers sometimes oblong, apically acute or acuminate, basally rounded or cordate to cuneate. Inflorescence axillary or forming a large, terminal, leafy, decussate-branched panicle, composed of small terminal involucrate corymbs or head like umbellets, each 2-7 flowered; peduncles and inflorescence-branches rather slender, acutely tetragonal; involucre 4-leaved, the bracts sessile, opposite, broadly obovate, often obcordate. Flowers sessile, pleasantly fragrant, medium-sized, opening at sunset, each subtended by 2 broadly ovate or elliptic bracts; corolla hypocrateriform, deciduous at sunrise, its tube Chinese-red to orange-red or orange, cylindric, 1-3 times as long as the calyx, 5-15 mm long, uniformly coloured outside and within, hairy at the base within, the mouth orange, the limb white, spreading, 5-8 (usually 6 or 7)-parted, more or less contorted, 5-6 mm wide, the segments imbricate in bud, obliquely triangular or elliptic, the exterior margin erose; stamens 2, inserted just below the mouth of the corolla-tube; filaments subobsolete; anthers ovate-cordate, 2-lobed, included, with a small spur on the back near the apex; style as long as or shorter than the corolla-tube, included; stigma capitate or peltate, glandular, with a central depression; ovary superior, ovate-globose, compressed; capsule cordate or suborbicular, about 2 cm long and wide, 3-4 mm wide, compressed, 2-celled, 2-valved, opening transversely from the apex; seeds 1 per cell, compressed.