Gonystylus

Family Thymelaeaceae. Order Myrtales.

Large trees to small trees. Buttresses present, or absent; short. Spines absent. Stilt roots absent. Bark not peeling in strips. Slash orange, red, brown. Vertical stripes in the inner bark or wood present. 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, or leathery; gland-dotted; symmetric at the base; not dissected; smooth margined. Epidermis not waxy. Venation pinnate. Secondary veins open, or closed; prominent, or not prominent, but visible. Smallest veins not prominent, but visible, or not visible; net like. 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; terminal; on a branched axis; specialized inflorescence units absent; numerous and persistent inflorescence bracts absent. Flowers bisexual; stalked; about 0.5 cm long or across, or to about 3 cm long or across; round; with male or female parts not raised on a column. Hypanthium present. Disk absent. Perianth present; with distinct calyx and corolla whorls. Sepals 3-7; partially joined; persistent in fruit; not growing any further after flowering. Epicalyx absent. Petals present; 7-40; free, or all joined; not fleshy; deciduous; not stalked; entire. Stamens 7-80(-100) (many); filaments present; free of each other; free of the perianth; all equal in size; isomerous, or diplostemonous. Anthers 2 loculed; attached by the base; not awned; dehiscing by long slits. Ovary superior. Carpels joined; 2-8. Locules 2-8. Styles solitary. Stigmas 1 lobed; distinctive; head shaped. Fruit capsular; non-fleshy; not multiple; splitting; not enclosed in, or sitting on, fleshy perianth parts; wingless. Seeds 1-5 per fruit; about 1 cm long, or much more than 1 cm long; wingless; uniform in cross-section; aril present; non-endospermic.

Outer bark dark brown; slash laminated and with irritant silky fibers; leaves often leathery with close secondary veins; gland dots usually appearing as "pin pricks" when held up to light; style sometimes with a few "parastyles:. Taxon images: gengonys.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.