Large trees to small trees. Buttresses absent. Spines absent. Stilt roots absent. Bark red, gray, brown; not peeling in strips. Slash yellow, orange, brown. Vertical stripes in the inner bark or wood absent. Odor absent. Exudate absent. Terminal buds not enclosed by leaves.
Complex hairs absent. Stinging hairs absent. Mature twig indumentum absent.
Leaves opposite; 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. Smallest veins not prominent, but visible, or not visible; net like, or ladder 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 present; joined; joined across twigs; encircling the twig; leafy; not fringed; large; persistent. Domatia absent. Basal glands absent. Hairs on mature leaf present, or absent; sparse.
Inflorescences present; terminal; on an unbranched axis, or on a branched axis; specialized inflorescence units present; specialized inflorescence units heads; numerous and persistent inflorescence bracts absent. Flowers bisexual; about 0.5 cm long or across; round; with male or female parts not raised on a column. Hypanthium absent. Disk present. Perianth present; with distinct calyx and corolla whorls. Sepals 4-5; partially joined; persistent in fruit; not growing any further after flowering. Epicalyx absent. Petals present; 4-5; all joined; not fleshy; deciduous; not stalked; entire. Stamens 4-5; filaments present; free of each other; joined to the perianth; all equal in size; isomerous; opposite the sepals (when isomerous). Anthers 2 loculed; attached by the base; not awned; dehiscing by long slits. Ovary superior. Carpels joined; 2. Locules 2. Styles solitary. Stigmas 1 lobed; not distinctive. Fruit capsular; non-fleshy; multiple; splitting; not enclosed in, or sitting on, fleshy perianth parts; wingless. Seeds 100 per fruit (many); barely visible; winged, or wingless; uniform in cross-section; aril absent; endospermic.
Twigs end in large and flattened buds, appearing like little leaves; stipules keeled; fruits multiple; seeds not winged. Taxon images: nauclea.gif gennauc.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.