Emergent trees to large trees. Buttresses present; tall. Spines absent. Stilt roots absent. Bark gray; not peeling in strips. Slash white, brown. Vertical stripes in the inner bark or wood present. Odor absent. Exudate absent. Terminal buds not enclosed by leaves.
Complex hairs present; disk-shaped, or star-like. Stinging hairs absent. Mature twig indumentum absent.
Leaves spiral, or two-ranked; not scale-like; simple; all of the same type; not modified into spines; coriaceous; not gland-dotted; symmetric at the base; not dissected; smooth margined. Epidermis not waxy. Venation pinnate. Secondary veins open; prominent, or not prominent, but visible. Smallest veins prominent; ladder like. Intramarginal vein present. Stalk of blade less than a quarter the length of the blade; not winged; attached to base of leaf blade; swollen; swollen at one end. Stipules present; free from one another; laterally placed; not encircling the twig; scale-like to leafy; not fringed; small; not persistent. Domatia present to absent. Basal glands absent. Hairs on mature leaf present; dense.
Inflorescences present; terminal, or axillary; on a branched axis; specialized inflorescence units absent; numerous and persistent inflorescence bracts absent. Flowers bisexual; stalked; about 0.5 cm long or across; round; with male or female parts not raised on a column. Hypanthium absent. Disk absent. Perianth present; with distinct calyx and corolla whorls. Sepals 5; free, or partially joined; persistent in fruit; with at least some sepals becoming wing-like; 2 becoming wing-like. Epicalyx absent. Petals present; 5; free; not fleshy; deciduous; not stalked; entire. Stamens 15-65(-100) (many); filaments present; joined; free of the perianth; all equal in size; triplostemonous to polystemonous. Anthers 2 loculed; attached by the base; awned; dehiscing by long slits. Ovary superior, or partly inferior. Carpels joined; 3. Locules 3. Styles solitary. Stigmas 1 lobed; not distinctive. Fruit a nut; non-fleshy; not multiple; not splitting; not enclosed in, or sitting on, fleshy perianth parts; winged. Seeds 1 per fruit; about 1 cm long; wingless; uniform in cross-section; aril absent; endospermic.
Large trees, usually buttressed; leaves with an intramarginal vein; fruit with five accrescent calyx lobes, 2 forming wings. Taxon images: genanidp.gif
Cite this publication as: Jarvie, J.K. and
Ermayanti (1996 onwards). `Tree Genera of Borneo - Descriptions and
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993) should also be cited.