Large trees to small trees. Buttresses present, or absent; short. Spines absent. Stilt roots absent. Bark gray, brown; not peeling in strips. Slash yellow. Vertical stripes in the inner bark or wood absent. Odor absent. Exudate absent. Terminal buds not enclosed by leaves.
Complex hairs present; disk-shaped, or star-like. Stinging hairs absent. Mature twig indumentum present, or absent; dense, or sparse.
Leaves spiral, or two-ranked; not scale-like; simple; all of the same type; not modified into spines; coriaceous, or paper-like; not gland-dotted; symmetric at the base; not dissected; smooth margined. Epidermis not waxy. Venation pinnate, or trinerved. Secondary veins open; prominent. Smallest veins not prominent, but visible, or not visible; net like, or box like. Intramarginal vein present, or absent. Stalk of blade less than a quarter the length of the blade to more than half the length of the blade; not winged; attached to base of leaf blade; not swollen, or swollen; swollen at one end, or swollen at both ends. Stipules present; free from one another; laterally placed; not encircling the twig; scale-like; not fringed; small; not persistent. Domatia absent. Basal glands absent. Hairs on mature leaf present, or absent; dense, or sparse.
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; partially joined; not persistent in fruit; not growing any further after flowering. Epicalyx absent. Petals present; 5; all joined; not fleshy; deciduous; not stalked; entire. Stamens 100 (many); filaments present; free of each other; free of the perianth; all equal in size; polystemonous. Anthers 2 loculed; attached by the base; not awned; dehiscing by long slits. Ovary superior. Carpels joined. Styles solitary. Stigmas 1 lobed; not distinctive. Fruit capsular, or drupaceous; fleshy; not multiple; splitting, or not splitting; not enclosed in, or sitting on, fleshy perianth parts; wingless. Seeds 1 per fruit; less than 5 mm; wingless; uniform in cross-section; aril absent; endospermic.
Small to large trees; leaves usually trinerved; in one BBBR species (J. cf rinoreoides) the quaternary veins covered in scales; fruits spiny, sometimes the spines soft and covered in simple and stellate hairs.
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.