Tetrathyrium Bentham.

Shrubs or small trees, evergreen or semievergreen; buds naked. Leaves shortly petiolate; stipules membranous; leaf blade membranous or thinly leathery, margin entire, venation pinnate. Inflorescence capitate, shortly spicate, or racemose, axillary or terminal, 3–25-flowered. Flowers bisexual, usually 4 or 5(or 6)-merous. Floral cup obconical, stellately pubescent. Sepals usually 4 or 5(or 6), ovate, pubescent, deciduous. Petals white or red, straplike, circinate in bud. Stamens 4 or 5(or 6), perigynous, anther thecae 2-sporangiate, each dehiscing by 2 valves, connective protrusion long and slender; disk scales present. Ovary inferior or semi-inferior; ovules 1 per locule. Fruiting pedicel short or absent. Capsules dehiscing by two 2-lobed valves, lower part enveloped by floral cup. Seeds 1 per carpel; endosperm fleshy.

Three species: China, E and N India, Japan; three species (two endemic) in China.