Alphitonia

Family Rhamnaceae. Order Rhamnales.

Large trees to shrubs. Buttresses absent. Spines absent. Stilt roots absent. Bark gray, brown; not peeling in strips. Slash yellow, green. Vertical stripes in the inner bark or wood absent. Odor absent, resinous, aromatic. Exudate absent. Terminal buds not enclosed by leaves.

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

Leaves two-ranked; not scale-like; simple; all of the same type; not modified into spines; coriaceous, or paper-like; not gland-dotted; symmetric at the base; not dissected; smooth margined. Epidermis waxy. Venation pinnate. Secondary veins open; prominent. Smallest veins prominent; net like, or 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; dense, or sparse.

Inflorescences present; terminal, or axillary; the flowers from a single point on the stem, or on a branched axis; specialized inflorescence units absent; numerous and persistent inflorescence bracts absent. Flowers bisexual; stalked; about 0.5 cm long or across; round; with male or female parts not raised on a column. Hypanthium present. Disk present; the stamens outside the disk. Perianth present; with distinct calyx and corolla whorls. Sepals 5; free; not persistent in fruit; not growing any further after flowering. Epicalyx absent. Petals present; 5; free; not fleshy; deciduous; stalked; entire. Stamens 5; filaments present; free of each other; joined to the perianth (joined to bottom of petals and enveloped by them); all equal in size; isomerous; alternating with the sepals (when isomerous). Anthers 2 loculed; attached along the side; not awned; dehiscing by long slits. Ovary inferior. Carpels joined; (2-)3. Locules (2-)3. Styles solitary. Stigmas (2-)3 lobed; not distinctive. Fruit drupaceous; non-fleshy; not multiple; not splitting; not enclosed in, or sitting on, fleshy perianth parts; wingless. Seeds 2-3 per fruit; less than 5 mm, or about 1 cm long; wingless; uniform in cross-section; aril present; endospermic.

Distichous and waxy leaves; petals stalked and enveloping the stamens; 2-3 styles; seeds enclosed by a loose red-brown aril. Taxon images: alphiton.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.