Xanthophyllum Roxb.

Shrubs or trees. Twigs terete, sometimes with annular or cap-like nodal glands. Axillary buds 2-8, serial, each with 2 bud scales. Leaves alternate (or spiral), sometimes shifted-decussate, stalked, nearly always with glands beneath, mostly near base of blade. Inflorescence axillary, branched or sometimes unbranched, panicle-or raceme-like. Flowers solitary or in lower half with 3 (rarely more) together. Sepals 5, free, usually slightly unequal, usually caducous after flowering. Petals 5, usually unequal, free; lower petal (carina) usually boat-shaped, clawed, apically inappendiculate. Stamens nearly always 8, rarely 7, 9, or 8-10; 4 epipetalous, 2 placed at the base of the carina and ad-nate with it or not, 2 alternipetalous and opposite the lateral sepals; filaments free or connate basally, rarely halfway connate, very rarely triadelphous; anthers tetrasporangiate, opening introrsely with slits. Disk annular. Gynoecium usually as long as androecium; ovary usually shortly stipitate, syncarpous, composed of 2 median carpels, 1-locular or sometimes semi-2-locular; style terminal; stigma slightly bilobed or sometimes peltate; ovules 2-seriate, 4 or (6-)8-c. 20, very rarely c. 40. Fruit indehiscent (or very rarely irregularly 2-valved, not in Mal.), globular or rarely ellipsoid, c. 1-15 cm, usually with a hard pericarp. Seed(s) 1 or 4-20, inappendiculate, glabrous; embryo large, flat or thick; albumen copious to nearly absent.

By far the majority of the species grow in the tropical lowland rain-forest, mostly below 500 m. About 10 spp. (of which 3 extra-Malesian ones) are usually found between 500-1200(-1500) m, but sometimes also lower. About a dozen species are sometimes found in freshwater swamp forests, but they are not confined to that habitat, except 63. X. ramiflorum. Also nearly all of the continental Southeast Asian species seem to be confined to the rain-forest; 60. X. lanceatum is restricted to stream banks and swamps; 62. X. virens occurs in monsoon forests, tolerating rather long dry periods. Otherwise the ecology is for all species 'rain-forest', not specifically repeated.