Description from Flora of China
Shrubs, deciduous. Winter buds with several pairs of scales. Leaves opposite, entire or sometimes sinuous, shortly petiolate, estipulate. Flowers forming a spike at apices of lateral branches, sometimes solitary in axils of upper leaves. Calyx cupular, 4- or 5-lobed. Corolla reddish or white, campanulate to funnelform or hypocrateriform, 4- or 5-lobed, regular; tube slightly gibbous at base, inside long pubescent or glabrous. Stamens 4 or 5, inserted in corolla tube, included or slightly exserted; anthers introrse. Ovary 4-locular, 2 locules with several sterile ovules, remaining 2 each with 1 fertile ovule; style slender; stigmas capitate or slightly 2-lobed. Fruit a berrylike drupe, white, red, or bluish black, globose, ovoid, or ellipsoid; pyrenes 2, ovoid, ± compressed; seeds with endosperm, embryo small.
Sixteen species: 15 in North America and Mexico; one species (endemic) in China.