Pisonia

Family Nyctaginales. Order Thymelaeales.

Large trees to shrubs. Buttresses absent. Spines present, or absent (Pisonia punctata). Stilt roots absent. Bark gray, brown; not peeling in strips. Slash brown. Vertical stripes in the inner bark or wood absent. Odor absent. Exudate absent. Terminal buds not enclosed by leaves.

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

Leaves opposite; not scale-like; simple; all of the same type; not modified into spines; coriaceous; not gland-dotted; symmetric at the base; not dissected; smooth margined. Epidermis not waxy. Venation pinnate. Secondary veins open; prominent, or not prominent, but visible. Smallest veins not prominent, but visible, or not visible; net 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 absent. Domatia absent. Basal glands absent. Hairs on mature leaf absent.

Inflorescences present; terminal, or axillary, or on the trunk or branches; 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 different plants; stalked; 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 sepals. Sepals 5, or 10 (rare); partially joined; persistent in fruit; growing slightly after flowering. Epicalyx absent. Petals absent. Stamens 2-40(-100) (many); filaments present; joined (base); free of the perianth; of different sizes; anisomerous to polystemonous. Anthers 2 loculed; attached by the base; not awned; dehiscing by long slits. Ovary superior. Carpels solitary; 1. Locules 1. Styles solitary. Stigmas 1 lobed; distinctive; head shaped, or fringed. Fruit an anthocarp; non-fleshy; not multiple; not splitting; not enclosed in, or sitting on, fleshy perianth parts; winged, or wingless. Seeds 1 per fruit; less than 5 mm; wingless; uniform in cross-section; aril absent; endospermic.

Fruits enclosed in a much elongated perianth. Taxon images: pisonia1.gif pisonia.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.