THAI FOREST BULLETIN (BOTANY) 36
at the angle between mid-vein and lateral nerves. Petiole glabrous or pubescent. Interpetiolar stipules broadly triangular, narrowly triangular, filiform or cuspidate, persistent or caducous, blackish at central area when dry, sometimes with secretory collectors present on the adaxial side. Inflorescences terminal on main or lateral branches, sessile or pedunculate, if pedunculate then erect or pendulous; brachiate dichasial cymes, compact or lax; peduncle short or sessile; axes, pedicels and calyces glabrous or covered with short hairs; order bracts with both stipular and foliar parts or with only stipular parts, the stipular parts triangular, broadly triangular or narrowly triangular, the foliar parts elliptic, triangular, narrowly triangular or forming small leaves, bracts present at the base of all branches, persistent or caducous. Flowers 5-merous, fragrant, bisexual, in threes (triads) at the branchlet ends, with bracteoles at the base all branches, persistent or caducous; the flowers of the triad with a short pedicel or sessile; bracteoles usually present except for the central flowers of the triads, opposite at the base of the ovary or on the pedicel, filiform or narrowly triangular with acuminate apex. Calyx green, hairy; tube short; lobes filiform, triangular, broadly triangular or ovate, with rounded or acute tips, as long as, shorter or longer than the inferior ovary. Corolla white, cream or greenish, tube cylindrical or funnel-shaped, on the inside the upper part near the throat pubescent (hairs silky or short) and the lower part glabrous, outside pubescent; lobes contorted to the left in bud, with rounded, acute or apiculate apex, the inner surface glabrous or pubescent at the base, the outer surface covered with spreading hairs, margins ciliate. Stamens inserted at the corolla throat, alternate with the corolla lobes, attached to the throat by a short filament, filaments tubular, glabrous; anthers linear, with short sterile apical appendix, basifixed, opening by means of longitudinal slits, twisted or not after spreading. Style-stigma complex conspicuously long-exserted, fusiform or club-shaped, densely soft hairy above or sparsely short hairy; the lower stylar portion slender, as long as, shorter or longer than the swollen upper part; the latter bearing stigmatic areas fused over most of the length, represented by papillate, longitudinal furrows, the 2 stigmas only free at their very tip. Ovary small, globose or ellipsoid, glabrous to densely hairy, with 2 locules, each containing a fleshy, peltate, axillary placenta, ovules one, a few or numerous, immersed in the placenta; disc conspicuous. Fruits berry-like, bilocular, globose, subglobose or ellipsoid, with short persistent calyx or calyx scar, glabrous or pubescent, dark green, greenish or whitish, black when ripe; endocarp membranaeous. Seeds 1-many per fruit, globose to subglobose with ± circular adaxial cavity in case of one seed per fruit, plano-convex in case of a few seeds per fruit and broadly triangular or angular in case of numerous seeds per fruit, brownish to black, testa with secondary thickenings; endosperm horny; embryo curved, with foliaceous cotyledons.
About 370 species in the tropics, with the highest number in Africa. Twenty-four species and one variety in Thailand.
KEY TO THE SPECIES (A) (based mainly on flowering material)
Mature inflorescences erect, peduncle straight
Corolla lobes elliptic; corolla bud stellate, with apiculate apex
Calyx lobes broadly triangular, shorter than the ovary
Calyx lobes linear, as long as or longer than the ovary