APOCYNACEAE  

Shrubs, lianas or trees up to 9 m high, with white latex; branches unarmed, with pale lenticels; branchlets terete, often sulcate when dry. Leaves opposite, those of a pair equal or subequal, shortly petiolate, with colleters in 1 or 2 rows in axils; lamina acuminate, rounded or cuneate at base. Inflorescences terminal, paniculate, several- to many-flowered, lax; lower bracts leafy; others narrowly oblong, acute, with colleters in axils. Flowers regular except for sometimes slightly unequal sepals, small. Calyx persistent beneath fruit; sepals green, connate at base, ovate, imbricate, entire, pubescent or glabrous outside, ciliate inside at base near edge with 0 or 1 triangular or ovate colleters (in whole flower 3-10). Corolla +/-trumpet-shaped; tube ventricose in middle, outside glabrous at base and minutely pubescent at apex; lobes overlapping to left in bud, elliptic, rounded, entire, ciliate. Stamens exserted, but covered by appendages; filaments short, filiform, glabrous outside; anthers introrse, sagittate at base, apiculate and pilose at apex, fertile for 1/2 of length just below apices. Pistil glabrous or sometimes with a few papillae; ovary superior, subglobose; carpels 2, free, rounded; disc none; style split at base; stigma minute, bilobed; ovules many, in several rows. Follicles 2, spreading, almost free, pendulous, slender, adaxially dehiscent, glabrous outside. Seeds many, in two or more rows, linear to very narrowly oblong, finely grooved, glabrous, with a +/-dense tuft of retrorse hairs at apices; embryo large, surrounded by very scanty whitish endosperm.

Trees or shrubs with white latex in all parts; branchlets glabrous. Leaves opposite, petiolate, those of a pair equal or subequal, elliptic to oblong, entire, glabrous. Inflorescence a compound, umbellate cyme, terminal or sometimes axillary, pedunculate. Flowers +/-regular, fragrant. Sepals connate at extreme base, imbricate, glabrous outside, with 2-4 rows of colleters at base. Corolla white to yellow, tube almost cylindric, often greenish, glabrous outside, pubescent inside below stamens; lobes overlapping to left in bud, entire, glabrous, spreading and later recurved. Stamens arising above middle of corolla tube, included; filaments very short, filiform, glabrous; anthers ovate in outline, cordate at base, glabrous, thecae 2, parallel, longitudinally dehiscent. Ovary of 2 separate glabrous carpels united at base by a disc-like thickening; ovules many per carpel; pistil head composed of a basal cylindric stigmatic part and a filiform stigmoid apex. Fruit composed of 2 separate divaricate, obovoid to ellipsoid mericarps with rounded apex and containing up to 80 seeds. Seeds somewhat angular, smooth, brown; testa hard; embryo straight, spathulate, surrounded by thick, rather hard starchy endosperm leaving a hole around radicle apex, cotyledons thick.

Large, woody climbers with slender stems, glabrous; latex clear. Leaves large, with long petioles, elliptic to broadly ovate. Inflorescences 3- to many-flowered, extra-axillary, pedunculate, bostrychoid, lax, with small floral bracts; pedicels filiform, +/-pendulous. Calyx fused at its swollen base, one colleter in each intersepal sinus. Petals not fused at base, lanceolate, lax. Corona gynostegial, tripartite [formula: C(is) + Cs]: Staminal corona (Cs) is supported by a C(is) consisting of interstaminal lobes connate to a skirt with appendages predominantly developed in staminal position; skirt membranous, basally +/-fused, interstaminal parts of C(is) sickle-shaped, bidentate, villous; staminal corona lobes (Cs) erect, lanceolate to obovate, with a basal hump. Gynostegium borne on a column; guide rails short, oblique, protruding. Anthers subquadrangular; pollinarium (sub)erect, pollinia broadly ovate to quadrangular, with pellucid germination mouth on inner margin, yellow, corpusculum elliptic; style head flat or depressed, white. Follicles long, slender, glabrous. Seeds not seen.

Shrubs or small trees with milky latex; spines and tendrils absent. Leaves opposite, obovate-oblong, oblong or elliptic; with petiolar glands; without domatia; stipules absent. Flowers often large and conspicuous, solitary or in few-flowered fasciculate cymes, terminal. Calyx : lobes imbricate, free to base, with many glandular scales inside at base. Corolla hypocrateriform; tube divided into 2 distinct regions of varying shape and proportions; lobes 5, with induplicate aestivation, straight in bud or twisted to the right. Stamens 5, sessile, inserted at base of upper region of corolla tube; anthers conniving in a cone around gynoecium, polliniferous in upper part only, joined to clavuncle by a retinacle. Receptacular disc cupular or represented by separate oppositipetalous scales, these sometimes united in pairs. Ovary of 2 free multi-ovulate carpels, glabrous or hairy; style pubescent; clavuncle swollen; stigma pointed or flared at apex, not bifid. Fruit of 2 follicular mericarps. Seeds linear-compressed with an apical coma; endosperm absent.

Shrubs or trees up to 40 m high; stems and leaves completely glabrous; latex present; spines and tendrils absent. Leaves opposite, oblong to elliptic, entire, +/-concolorous; petiolate; stipules absent. Inflorescences cymose, terminal, rarely also axillary, few- to many-flowered; pedicels present, up to 10 mm long. Calyx glabrous; lobes free or connate at extreme base, herbaceous, imbricate, not revolute, with colleters inside covering part of ventral surface of sepals. Corolla hypocrateriform, externally glabrous, internally hairy above and below stamens; tube not developing splits (as in Pleiocarpa) ; lobes contorted, overlapping to the left, not ciliate. Stamens included, arising at or above middle of corolla tube; filaments short, anthers dorsifixed, longitudinally dehiscent, introrse, without carina. Ovary of 2 separate, glabrous mericarps diverging at 90-180deg, with 2-30 ovules per mericarp; pistil head composed of a subglobose basal stigmatic part and a stigmoid apex. Fruit composed of 2 separate diverging subglobose to obovoid, fleshy to fibrous mericarps. Seeds somewhat angular, smooth, brown; embryo straight, spathulate, surrounded by thick, rather starchy and hard endosperm, leaving a hole around radicle base; cotyledons thin, leafy, radicle almost cylindric.