Description from Flora of China
Shrubs erect, rarely climbing, rarely spinescent. Branchlets opposite. Leaves opposite, exstipulate, veins 3-5, basifugal, margin entire or serrate. Inflorescences racemose, paniculate, or cymose, rarely 1-flowered. Flowers fragrant. Calyx tube campanulate or turbinate, adnate to ovary; lobes 4(or 5). Petals 4(or 5), white, contorted. Stamens 13-90; filaments flat, free or basally connate; anthers ovoid or oblong, rarely globose. Ovary inferior or subinferior, 4(or 5)-loculed; placentation axile; ovules numerous, pendulous. Style (3 or)4(or 5)-lobed; stigmas clavate or spatulate. Fruit a capsule, 4(or 5)-valved, dehiscing by valves; epicarp papery; endocarp corky. Seeds numerous.
About 70 species: mainly in temperate regions of the N hemisphere; 22 species (17 endemic) in China.
(Authors: Huang Shumei (Hwang Shu-mei); Hideaki Ohba, Shinobu Akiyama)