Description from Flora of China
Shrubs, low, erect, unarmed or with spinescent branches; branches at base with a pair of reduced, usually deciduous leaves and a persistent stipule. Raphides apparently absent. Leaves opposite, sometimes fasciculate on unexpanded axillary stems and appearing whorled, subsessile, without domatia; stipules deciduous, interpetiolar or fused to petiole bases, 2-lobed, lobes gland-tipped. Inflorescences terminal, pseudoaxillary, or terminal on paired lateral short shoots and appearing axillary, congested-cymose to umbelliform or fasciculate, few to many flowered, often nodding, sessile to pedunculate; bracts reduced or occasionally leaflike. Flowers pedicellate, bisexual, apparently monomorphic. Calyx limb 5-lobed essentially to base. Corolla white, pink, or pale yellow, salverform to funnelform, glabrous inside; lobes 5, convolute in bud. Stamens 5, inserted in corolla throat, exserted; filaments short; anthers dorsifixed near base. Ovary 2-celled, ovules 1 in each cell, pendulous from apex; style curved; stigma clavate to ellipsoid and 2-lobed for a third to half its length, exserted. Fruit schizocarpous, dry, oblanceoloid, with calyx limb persistent; mericarps 2, indehiscent, each with 1 seed, ellipsoid, crustaceous; seeds medium-sized, ellipsoid; testa leathery; endosperm absent; embryo linear-oblanceolate.
The presence or absence of raphides has not been specifically noted anywhere we have seen; their absence is presumed here based on observations of specimens and the classification by Robbrecht (Opera Bot. Belg. 1: 1-271. 1988) of this genus in Antirrhoideae. W. C. Ko (in FRPS 71(2): 1. 1999) described the anthers as partially exserted, but these are fully exserted at anthesis on the specimens studied. On the few specimens studied (T. T. Yü 1348, C. Schneider 2194, Forrest 10713, all A; Boufford et al. 35041, MO), the flowers appear to be protandrous, with the stamens apparently dehiscing while the stigmas are enclosed in the corolla; on these plants subsequently the style elongates, the stigma is exserted by several millimeters, and then the two lobes separate and presumably become receptive.
● One species: China.
(Authors: Chen Tao (陈涛); Charlotte M. Taylor)