Ptychopyxis

Family Euphorbiaceae. Order Euphorbiales.

Small trees to shrubs. Buttresses absent. Spines absent. Stilt roots absent. Bark gray, brown; not peeling in strips. Exudate absent. Terminal buds not enclosed by leaves.

Complex hairs absent. Stinging hairs absent. Mature twig indumentum present; dense, or sparse.

Leaves spiral; not scale-like; simple; all of the same type; not modified into spines; coriaceous to leathery; not gland-dotted; symmetric at the base; not dissected; smooth margined. Epidermis not waxy. Venation pinnate. Secondary veins open; prominent. Smallest veins prominent; ladder like. Intramarginal vein absent. Stalk of blade a quarter to one half the length of the blade; not winged; attached to base of leaf blade; swollen; swollen at both ends. 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; sparse.

Inflorescences present; axillary, or on the trunk or branches (Ptychopyxis grandiflorus); 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; stalked; with the parts barely visible to the eye to 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 distinct calyx and corolla whorls. Sepals 4-6 (4-5 male, 6 female); partially joined; persistent in fruit; not growing any further after flowering. Epicalyx absent. Petals absent. Stamens 100 (many); filaments present; free of each other; free of the perianth; all equal in size; triplostemonous, or polystemonous. Anthers 4 loculed; attached by the base; not awned; dehiscing by long slits. Ovary superior. Carpels joined; 3. Locules 3. Styles solitary. Stigmas 3 lobed; not distinctive. Fruit capsular; fleshy, or non-fleshy; not multiple; splitting; not enclosed in, or sitting on, fleshy perianth parts; wingless. Seeds 1-3 per fruit; less than 5 mm, or about 1 cm long; wingless; uniform in cross-section; aril absent; endospermic.

Petioles long; tertiary venation prominent and scalariform; twigs often covered in simple hairs; fruits very shortly hairy; seeds with a fleshy jacket. Taxon images: ptychop.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.