Description from Flora of China
Sakakia Nakai; Tristylium Turczaninow.
Shrubs or trees, evergreen. Leaves petiolate; leaf blade margin entire or serrulate. Flowers bisexual, axillary, solitary or several in a cluster. Pedicel 1 cm or more, apically thickened; bracteoles 2, caducous, small, inserted near pedicel apex. Sepals 5, imbricate, unequal, basally slightly connate; outer sepals persistent, small. Petals 5, imbricate, basally connate. Stamens 25-30; filaments distinct, glabrous; anthers basifixed, 2-loculed, longitudinally dehiscent, with filiform trichomes, connective apiculate. Ovary usually glabrous, 2- or 3-loculed with 8-16 ovules per locule, placentation axile; style 1, persistent, slender, elongated, apically 2- or 3-lobed. Fruit baccate, ovoid to oblate, with several seeds per locule. Seeds blackish brown, reniform-globose to compressed globose, foveolate, shiny, glabrous; endosperm sparse; embryo curved.
Unlike Cleyera japonica, the Thunberg description of the genus Cleyera did not include elements of a mixed collection with Ternstroemia.
About 24 species: China, N India, Japan, Korea, Myanmar, Nepal, N Vietnam; tropical America; nine species (seven endemic) in China.