Description from Flora of China
Balanocarpus Beddome; Dioticarpus Dunn; Hancea Pierre (1891), not Seman (1857), nor Hemsley (1890); Peirrea F. Heim (1891), nom. cons., not Hance (1877); Petalandra Hasskarl (1858), not F. Mueller (1856).
Trees evergreen, of main canopy or understory, white resinous. Stipules caducous, small; leaf blade thinly leathery; lateral veins pinnate; tertiary veins scalariform (in Chinese species) [or subreticulate], margin entire. Flowers sessile or shortly pedicellate, in lax panicles of unilateral racemes; bracts early caducuous, linear. Calyx segments imbricate. Exposed parts of petals usually pubescent in bud. Stamens (10-)15, slightly connate and adnate to petals; anthers ovoid, small, subequal; connectival appendages aristate or filiform. Ovary ovoid, with prominent filiform style, or hourglass-shaped, with short tapering style. Fruit ovoid or globose; pericarp usually thin, waxy; 1-seeded, closely surrounded by thickened base of calyx segments; 2 fruit sepals winglike, linear, or all orbicular or ovate, subequal.
These trees are a source of a damar resin used in varnishes. The wood is finely grained, very durable, and used for making boats, bridges, and furniture.
About 100 species: Cambodia, China, S India, Indonesia, Laos, Malaysia, Myanmar, Papua New Guinea, Philippines, Thailand, Vietnam; four species (one endemic) in China.