Jackiopsis

Family Rubiaceae. Order Rubiales.

Large trees to small trees. Buttresses present; short. Spines absent. Stilt roots absent. Bark 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. Smallest veins not prominent, but 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 present; joined; joined across twigs; encircling the twig; leafy; fringed; large; persistent. Domatia absent. Basal glands absent. Hairs on mature leaf present; dense, or sparse.

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

Stipules ochreate and long lobed.


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.