Description from Flora of China
Trees, evergreen; terminal buds perulate, narrowly ovoid. Leaves petiolate; stipules usually present, minute, caducous or connate with petiole, leaving small scars; leaf blade lanceolate to ovate or obovate, leathery, discolorous, margin usually crenate-serrate, occasionally entire, venation pinnate. Plants monoecious. Male inflorescence a globose to shortly cylindrical, pedunculate, many-flowered, head, grouped in terminal or subterminal, compound racemes or panicles; each flower with 1–4 basal bracts. Female inflorescences capitate, subterminal or in lower part of male inflorescence, long-pedunculate, 5–30-flowered. Flowers unisexual. Sepals and petals absent. Male flowers: stamens (4 to) many; filaments very short or absent; anthers obovate-ovoid, thecae 2-sporangiate, each dehiscing by a longitudinal slit or rudimentary valve, apex truncate. Female flowers: staminodes (also interpreted as carpellodes) absent or needlelike; ovary semi-inferior; ovules ca. 30–50 per locule, axile; styles subulate, divergent, often strongly recurved; stigmas papillose, caducous or basal parts persistent in fruit. Infructescences globose, base truncate. Capsules woody, dehiscing loculicidally by two 2-lobed valves; staminode teeth and styles not persistent. Seeds many, upper ones sterile, wingless; one or a few lower ones fertile, flattened, narrowly winged along margin or only at apex; seed coat thick and hard; endosperm thin. 2n = 32.
The resin is used in medicine and perfumes, and the timber for making furniture.
About 11 species: Bhutan, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, N Thailand, Vietnam; eight species (five endemic) in China.