Rhus

Family Anacardiaceae. Order Sapindales.

Small trees to shrubs, or climbers. Buttresses absent. Spines absent. Stilt roots absent. Bark gray, brown; not peeling in strips. Exudate present; colorless; spotty; blackening on exposure to air. Terminal buds not enclosed by leaves.

Complex hairs absent. Stinging hairs absent. Mature twig indumentum absent.

Leaves spiral; not scale-like; simple, or compound; with three leaflets, or pinnate; with a terminal leaflet; leaflets opposite, or leaflets alternate; all of the same type; not modified into spines; coriaceous; not gland-dotted; very asymmetric at the base, or 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, or ladder like. Intramarginal vein absent. Stalk of blade less than a quarter the length of the blade; winged, or not winged; attached to base of leaf blade; not swollen. Stipules absent. Domatia present, or absent; pit-like; scattered along midrib. Basal glands absent. Hairs on mature leaf present; sparse.

Inflorescences present; terminal, or axillary; on a branched axis; specialized inflorescence units absent; numerous and persistent inflorescence bracts absent. Flowers bisexual, or 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 present; the stamens outside the disk. 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; 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. Styles solitary. Stigmas 1-3 lobed (1 or 3); distinctive; head shaped. Fruit drupaceous; fleshy; not multiple; 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; non-endospermic.

Leaves compound; secondary veins forking near the margin, not quite forming an intramarginal vein; style asymmetric in fruit; stigmas 3. Taxon images: genrhus.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.