Large trees to small trees. Buttresses present, or absent; tall, or short. Spines absent. Stilt roots absent. Bark gray, brown; not peeling in strips. Slash red, brown. Vertical stripes in the inner bark or wood absent. Odor absent. Exudate absent. Terminal buds not enclosed by leaves.
Complex hairs present, or absent; disk-shaped. Stinging hairs absent. Mature twig indumentum absent.
Leaves spiral; not scale-like; compound; pinnate; without a terminal leaflet; leaflets opposite, or leaflets alternate; all of the same type; not modified into spines; coriaceous; not gland-dotted; very asymmetric at the base, or symmetric at the base; not dissected; smooth margined, or with small to large teeth on margin. Epidermis not waxy. Venation pinnate. Secondary veins open; prominent. Smallest veins not prominent, but visible, or not visible; net like. Intramarginal vein present, or absent. Stalk of blade less than a quarter the length of the blade; not winged; attached to base of leaf blade; not swollen. Stipules absent. Domatia present, or absent; appearing as hair tufts; scattered along midrib. Basal glands absent. Hairs on mature leaf present, or absent; sparse.
Inflorescences present; terminal, or axillary; on an unbranched axis; specialized inflorescence units absent; numerous and persistent inflorescence bracts absent. Flowers at least some flowers unisexual; with male and female flowers on the same plant; not stalked; with the parts barely visible to the eye, or about 0.5 cm long or across; round to with one plane of symmetry; with male or female parts not raised on a column. Hypanthium absent. Disk absent. Perianth present; with all whorls looking like tepals. Tepals 3-4. Stamens 4-13; filaments present; free of each other; free of the perianth; all equal in size; isomerous to triplostemonous. Anthers 2 loculed; attached by the base; not awned; dehiscing by long slits. Ovary inferior. Carpels joined; 2. Locules 1. Styles solitary. Stigmas 2(-4) 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; less than 5 mm; wingless; uniform in cross-section; aril absent; endospermic.
Compound leaves with opposite to subopposite leaflets; flowers small and in spikes; fruit a nut enclosed in a papery 3-winged bract. Taxon images: genengel.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.