Liana; stems terete except when very young, minutely puberulent and lenticellate; sap milky, forming droplets near periphery of stems. Leaves pinnate, glabrous but with puberulent petioles, rachises, and midribs on upper sides; stipules ovate, small; petioles to 10 cm long; petiole and rachis winged; leaflets 5, oblong-elliptic, obtuse to acuminate at apex, obtuse at base, 7-23 cm long, 3-9 cm wide, punctate on both surfaces (especially below), bearing axillary tufts below, entire, sometimes with a single tooth on each side. Inflorescences slender, usually unbranched, upper-axillary, usually to 12 cm long (to 25 cm long in fruit); flowers white, to ca 3 mm long, solitary or in few-flowered thyrses; sepals 5, tomentulose, unequal (2 reduced), 1 concave and partially enclosing the anterior petals; petals 4, glabrous, the scales shorter, their reflexed appendages villous, their crests yellow, bilobed, the lobes slender, the anterior petals subtended by glands, the glands large, orange, erect, flattened, puberulent outside, glabrous inside; stamens 8, shorter than petals; filaments villous, weakly fused at base; ovary ovoid, terete, densely tomentose; styles short, stout. Capsules globose to broadly clavate, beaked at apex, gradually narrowed to stipitate base, densely rufous-tomentose, to 2 cm long and 1.5 cm wide; valves thin; seed 1, ellipsoid, laterally compressed, ca 1.2 cm long. Croat 6731, 12841. Common along the shore and in the canopy of the forest. Flowers in the late rainy season through the early dry season (October to February). The fruits mature in the dry season. Probably the most common Paullinia in the canopy. The species is most easily confused with P. pinnata, butcan be distinguished by having a terete stem and a densely rufous-tomentose fruit. Vegetation dries dark grayish in contrast to the green of P. pinnata. Known only from Panama, from tropical moist forest in the Canal Zone, Chiriqui, and Darien and from tropical wet forest in Panama (Cerro Jefe).