Description from Flora of China
Trees or erect shrubs. Leaf blade often with pellucid dots. Inflorescences axillary or superaxillary, cymose, pedunculate or sessile, 1- or several flowered. Flowers bisexual. Sepals 3, smaller than outer petals. Petals 6, in 2 whorls, free, each whorl valvate; outer petals ovate or obovate, usually smaller than inner petals (± equal in Orophea hainanensis and O. laui); inner petals with base narrowly clawed, apical limbs lozenge-shaped and cohering by margins to form a mitriform cap, apex usually acute or acuminate and sometimes extended, thickened, and recurved. Stamens 3-14; anther locules ovoid, extrorse; connectives apically acute or obtuse but not truncate. Carpels 3-15, free; ovules 1-4 per carpel; stigmas sessile or subsessile, capitate or ellipsoid. Fruit apocarpous; monocarps shortly stipitate, usually globose or oblong, sometimes constricted between seeds. Seeds 1-4 per monocarp.
All the Chinese species of Orophea belong to O. subg. Sphaerocarpon Kessler, distinguished by carpels with 2(or 3) ovules per carpel producing globose monocarps with hemispherical seeds. Mezzettiopsis is included here following Leonardía and Kessler (Blumea 46: 141-163. 2001).
About 37 species: S and SE Asia; six species (three endemic) in China.
(Authors: Li Bingtao (李秉滔 Li Ping-tao); Michael G. Gilbert)