Large trees to shrubs. Buttresses absent. Spines absent. Stilt roots absent. Bark gray, brown; not peeling in strips. 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 present, or absent; dense, or sparse.
Leaves spiral; 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, or wavy margined, or with small to large teeth on margin. Epidermis not waxy. Venation pinnate. Secondary veins open; prominent. Smallest veins prominent, or not prominent, but 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 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, or represented by solitary flowers only; terminal, or axillary; the flowers from a single point on the stem, or on an unbranched axis, or on a branched 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; about 0.5 cm long or across; round; with male or female parts not raised on a column. Hypanthium absent. Disk present; the stamens outside the disk, or the stamens on the disk. Perianth present; with distinct calyx and corolla whorls. Sepals 5; partially joined; persistent in fruit; not growing any further after flowering. Epicalyx absent. Petals present; 5; free; not fleshy; deciduous; not stalked; entire. Stamens 5; filaments present; free of each other; free of the perianth; all equal in size; isomerous; opposite the sepals (when isomerous). Anthers 2 loculed; attached along the side; not awned; dehiscing by long slits. Ovary superior. Carpels joined; 3. Locules 1-3. Styles solitary. Stigmas 3 lobed; not distinctive. Fruit capsular; non-fleshy; not multiple; splitting; not enclosed in, or sitting on, fleshy perianth parts; wingless. Seeds 1-6 per fruit; less than 5 mm; wingless; uniform in cross-section; aril present; endospermic.
Veins of mature leaves widely spaced and generally with an intramarginal vein set well into the lamina; capsule tipped by persistent style; seeds enveloped in crimson arils. Taxon images: gencelas.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.