Shrubs. Stems obtusely 4-sided, scabrous; branchlets 4-sided. Leaves petiolate; leaf blade papery, secondary veins 2 on each side of midvein, margin remotely serrulate. Inflorescences terminal, cymose or corymbose; bracts small, with dense stellate trichomes. Pedicel with dense stellate trichomes. Hypanthium funnelform-campanulate, obtusely 4-sided, 8-ribbed. Calyx lobes orbicular, winged on ridges. Petals white to pink, broadly obovate, oblique. Stamens 8, curved, shortly beaked, whorls unequal in length; connective inflated at middle. Ovary half inferior, urceolate, 4-celled. Style exserted from corolla. Capsule urceolate, longitudinally dehiscent.

The genus was revised by Hansen (Nord. J. Bot. 10: 21-23. 1990), but placed in the synonymy of Oxyspora by Maxwell (Gard. Bull. Singapore 35: 209-226. 1983 ["1982"]).

The leaves are very similar to those of Blastus pauciflorus, and sterile material is therefore difficult to identify.

● One species: China (Yunnan).