Large trees to small trees. Buttresses present, or absent; short (rare). Spines absent. Stilt roots present, or absent. Bark brown; not peeling in strips. Slash orange, red. Vertical stripes in the inner bark or wood absent. Odor absent. Exudate present; red; flowing, or spotty; not blackening on exposure to air. Terminal buds not enclosed by leaves.
Complex hairs absent. Stinging hairs absent. Mature twig indumentum present, or absent; sparse.
Leaves two-ranked; not scale-like; simple; all of the same type; not modified into spines; coriaceous; gland-dotted, or not gland-dotted; symmetric at the base; not dissected; smooth margined. Epidermis waxy, or not waxy. Venation pinnate. Secondary veins open; prominent, or not prominent, but visible. Smallest veins not prominent, but visible, or not visible; net like (loose). Intramarginal vein present. Stalk of blade less than a quarter the length of the blade; not winged; attached to base of leaf blade; not swollen. Stipules absent. Domatia absent. Basal glands absent. Hairs on mature leaf present, or absent; dense, or sparse.
Inflorescences present; axillary; 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 the same plant, or with male and female flowers on different plants; stalked; with the parts barely visible to the eye, or 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 all whorls looking like tepals. Tepals 3(-4). Stamens 6-12; filaments present; joined; free of the perianth; all equal in size; diplostemonous, or triplostemonous. Anthers 2 loculed; not awned; dehiscing by long slits. Ovary superior. Carpels solitary; 1. Locules 1. Styles solitary. Stigmas 2 lobed; not distinctive. Fruit follicular; fleshy; not multiple; splitting; not enclosed in, or sitting on, fleshy perianth parts; wingless. Seeds 1 per fruit; about 1 cm long, or much more than 1 cm long, or more than 10 cm long; wingless; with folds like marble, in cross- section; aril present; endospermic.
Leaf veins distant and looping; tertiary veins almost invisible, when so, forming a loose network; anthers free at sides and tops; aril divided almost to base. Taxon images: gymna.gif
Cite this publication as: Jarvie, J.K. and
Ermayanti (1996 onwards). `Tree Genera of Borneo – Descriptions and
Illustrations’ URL
http://django.harvard.edu/users/jjarvie/Borneo.htm/.
Dallwitz (1980) and Dallwitz,
Paine and Zurcher (1993) should also be cited.
