Description from Flora of China
Shrubs or trees. Leaves alternate, petiolate; stipules deciduous or evergreen, small, pinnately veined; leaf blade simple, elliptic to lanceolate, secondary veins spreading or curved, margin glandular dentate or spinose dentate, rarely crenate or entire. Inflorescence terminal or axillary, a raceme or racemose panicle, many flowered. Flowers bisexual or also unisexual, small. Calyx tube adnate to base of ovary; lobes 5, persistent. Petals 5, perigynous, erect or reflexed at anthesis, white or yellowish green, valvate. Stamens 5, inserted at margin of disc; filaments filiform-subulate; anthers ovoid to oblong. Disc ringlike. Ovary superior or semi-inferior, attached to disc, 2-carpellate, long ellipsoid; placentation central; ovules numerous, 2-seriate. Style simple or sometimes divided to middle, striate; stigma capitate. Fruit a capsule, conical to linear-oblong, apex cleft, with persistent calyx lobes and petals. Seeds numerous and narrowly fusiform or few and flattened oblong; seed coat glossy; embryo cylindric, large.
About 27 species: mainly in SE Asia and the Himalayas to China and Japan, one species in North America; 15 species (ten endemic) in China.
(Authors: Jin Shuying ; Hideaki Ohba)