Large trees to small trees. Buttresses absent. Spines absent. Stilt roots absent. Bark gray; not peeling in strips. Slash cream. 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, or star-like. Stinging hairs absent. Mature twig indumentum present, or absent; dense, or sparse.
Leaves opposite, or spiral; not scale-like; simple; of different sorts on a single twig, or all of the same type; not modified into spines; coriaceous; gland-dotted, or not gland-dotted; symmetric at the base; not dissected; smooth margined, or with small to large teeth on margin. Epidermis not waxy. Venation pinnate, or trinerved, or palmate. Secondary veins open; prominent. Smallest veins prominent, or not prominent, but visible; ladder like. Intramarginal vein present, or absent. Stalk of blade absent to a quarter to one half the length of the blade; not winged; attached to surface of leaf blade, attached to base of leaf blade; not swollen, or swollen; swollen at one end. Stipules present; free from one another; laterally placed; not encircling the twig; scale-like, or leafy; 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, or leaf-opposed; 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 different plants; not stalked, or stalked; about 0.5 cm long or across; round; with male or female parts not raised on a column. Hypanthium absent. Disk present, or absent; the stamens outside the disk. Perianth present; with distinct calyx and corolla whorls. Sepals 3-5; free; not persistent in fruit; not growing any further after flowering. Epicalyx absent. Petals absent. Stamens 16-100 (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; 3. Locules 3. Styles solitary, or free; 3. Stigmas 1-3 lobed (1 or 3); not distinctive. Fruit capsular; non-fleshy; not multiple; splitting; not enclosed in, or sitting on, fleshy perianth parts; winged, or wingless. Seeds 6 per fruit; less than 5 mm; wingless; uniform in cross-section; aril absent; endospermic.
Leaves spiral or opposite; small glands often found on lower surface of leaves; fruits often spiny. Taxon images: mallotus.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.