Trema

Family Ulmaceae. Order Urticales.

Large trees to small trees. Buttresses present, or absent; short. 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 present, or absent; star-like. Stinging hairs absent. Mature twig indumentum absent.

Leaves two-ranked; not scale-like; simple; all of the same type; not modified into spines; coriaceous; not gland-dotted; very asymmetric at the base to symmetric at the base; not dissected; with small to large teeth on margin. Epidermis not waxy. Venation trinerved. Secondary veins open; prominent. Smallest veins prominent, or not prominent, but visible; ladder like. Intramarginal vein 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; 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; stalked; with the parts barely visible to the eye; 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; free; persistent in fruit; not growing any further after flowering. Epicalyx absent. Petals absent. 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; 2. Locules 1. Styles solitary. Stigmas 2 lobed; not distinctive. 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; with folds like marble, in cross- section; aril absent; endospermic, or non-endospermic.

Taxon images: trema.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.