Large trees to small trees. Buttresses present, or absent; short. Spines absent. Stilt roots absent. Bark gray, brown; not peeling in strips. Slash gray, 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; fleshy; gland-dotted, or not gland-dotted; symmetric at the base; not dissected; smooth margined. Epidermis not waxy. Venation pinnate. Secondary veins open; not visible. Smallest veins not visible. Intramarginal vein present, or absent. Stalk of blade absent to less than a quarter the length of the blade; not winged; attached to base of leaf blade; not swollen. Stipules present, or absent; free from one another; laterally placed; not encircling the twig; scale-like; not fringed; small; persistent. Domatia absent. Basal glands absent. Hairs on mature leaf present, or absent; sparse.
Inflorescences present, or represented by solitary flowers only; axillary; the flowers from a single point on the stem (1 or 2); specialized inflorescence units absent; numerous and persistent inflorescence bracts absent. Flowers bisexual; stalked; about 0.5 cm long or across to to about 3 cm long or across; round; with male or female parts raised on a column, or not raised on a column; with the female parts of the flower raised on a stalk. Hypanthium present. Disk absent. Perianth present; with distinct calyx and corolla whorls. Sepals 6; free, or partially joined; persistent in fruit; not growing any further after flowering. Epicalyx absent. Petals present; 6; free; not fleshy; deciduous; not stalked; entire. Stamens 12-18; filaments present; free of each other; free of the perianth; all equal in size; diplostemonous, or triplostemonous. Anthers 2 loculed; attached along the side; not awned; dehiscing by long slits. Ovary partly inferior. Carpels joined; 2-4(-6). Locules 2-4(-6). Styles solitary. Stigmas 1 lobed; distinctive; head shaped. Fruit capsular; non-fleshy; not multiple; splitting; not enclosed in, or sitting on, fleshy perianth parts; wingless. Seeds 100 per fruit (many); barely visible; winged; uniform in cross-section; aril absent; non-endospermic.
Leaves opposite; axillary buds elongated and pointed; flowers showy and purple; fruits woody capsules sitting on persistent calyx; seeds long winged.
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.