Tendrilled lianas; trunks to 7 cm diam., involuted, twisted, warty, at least sometimes without milky sap; stems with milky sap, glabrous to villous especially when young, (3-) 5-ribbed, the ribs on larger stems in turn 2-ribbed, often sparsely armed with short prickles, especially on larger stems; tendrils bifid, axillary. Leaves biternate to 2-or 3-pinnate, 10-40 cm long, often much reduced on the inflorescence, 9-26-foliolate; petioles with marginal ribs above; rachis winged; leaflets ovate to elliptic, obovate or oblanceolate, acute to bluntly acuminate, the acumen often rounded and apiculate, rounded to attenuate at the base, 2-8 cm long, 1.5-5 cm wide, glabrous to sparsely pubescent, especially on the veins, the margin sinuate-dentate near the apex, conspicuously dentate on juveniles, often conspicuously notched on both sides beneath the acumen; stipules deltoid-linear, ca. 5 mm long, to ca. 1 cm long on juveniles. Thyrses in solitary racemes in leaf axils, on tendrils, or in terminal or axillary racemose panicles; pedicels slender, 1-3 mm long, densely puberulent. Flowers white, sweetly aromatic, 2.5-3.5 mm long; calyx tomentose, the sepals elliptic, to ca. 2.5 mm long, reflexed or spreading at anthesis; petals spatulate to obovate, 2-3.5 mm long, fused at the base with the disc glands, the anterior scales orbicular, nearly 3 as long as petals, the deflexed appendages slender, glabrous or sparsely pubescent except along their common inner margin, attached laterally to the appendage of neighboring scales by vil-lous pubescence, pendent nearly to the base of scale, the crest yellow, hammer shaped; disc glands 4, large, ovoid, orange, glabrous; filaments flattened, sparsely villous; bisexual flowers with the stamens 1.5-2 mm long, the ovary and style together 2.5-3 mm long, the stigmas ca. 1 mm long, the ovary glandular, sparsely hispidulous medially, the style short, the style and stigmas sparsely hispidulous; staminate flowers with the stamens 2.5-3 mm long, the pistil ca. 0.5 mm long, the ovary 3-sided, glabrous. Fruits ovate-cordate, 1.7-2.7 cm long, glabrous, the seed-bearing part with raised veins, the wing usually scarcely if at all constricted below the seed-bearing part.
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