Tendriled herbaceous vine, probably ultimately arising from a woody stern; at least smaller stems, petioles, and veins of leaf blades (especially below) densely and inconspicuously puberulent; the same parts but also the axes of the inflorescences, pedicels, and leaf surfaces often sparsely pubescent with flattened, +/- appressed, T-shaped trichomes; stems of juvenile parts often white-speckled. Leaves simple, thin, usually drying dark, dimorphic; larger leaves borne below the inflorescences, on petioles mostly 7-11 cm long, ovate-cordate, as broad or nearly as broad as long, 9-15 cm long and 9-12 cm wide, the lateral veins above sinus in 3-6 pairs, extending into apiculate teeth along margins of blade, a single strong trunk vein extending into each basal lobe, the sinus about as deep as broad; smaller leaves higher on stem and opposite inflorescences, on petioles mostly 2-8 cm long, usually narrowly ovate, truncate to obtuse or acute at base (rarely cordate), mostly 3-10 cm long and 2-8 cm wide, otherwise like larger leaves. Cymes terminal or opposite upper leaves, small, congested, branched, umbelliform, 1-4 cm long, about as broad as long; peduncles mostly 2-10 mm long at anthesis (somewhat longer in fruit), densely appressed-pubescent with T-shaped trichomes, densely bracteate at apex, the bracts minute with margins glabrous or very inconspicuously ciliate; pedicels terete, 1.5-3.5 mm long, sparsely pubescent, the trichomes as on peduncles but usually smaller; calyx spreading, +/- bowl-shaped, inconspicuously 4-lobed, narrower than buds, nearly glabrous; buds ovoid, 1.5-2 mm long, drying with ridges along margins of petals; petals 4, free, broadly oblong, obtuse and cucullate at apex inside, usually white or cream (rarely red); stamens opposite petals; filaments to ca 1 mm long, equaling or longer than anthers; anthers nearly as broad as long, dehiscing laterally; stigma simple, to ca 1.5 mm long. Fruits +/- globose, to 6 mm diam, apparently green at maturity; exocarp and mesocarp thin; seed 1, round, only slightly smaller than dimensions of fruit. Croat 7017 (type) Occasional, along the shore and at the edge of the Laboratory Clearing. Flowers at the beginning of the dry season in December and January on BCI (rarely elsewhere as late as March) or in the rainy season (late July to October); individual plants may flower for 1 month or more. The fruits develop promptly, are usually present with flowers, and are usually gone by March. The fruits are probably dispersed by small to medium-sized birds. It is not known whether the fruits become brightly colored. Observations on BCI indicate that the fruits are probably removed before turning color. Cissus pseudosicyoides has been confused with C. sicyoides (Croat, 1973), but can be distinguished most easily by its pubescent pedicels, dimorphic leaves, and T-shaped trichomes on the midrib of the blade. Costa Rica (Guanacaste Province) to northern Colombia. In Panama, widespread in lowland areas; known principally from the Pacific slope in drier areas of tropical moist forest, but also from premontane dry forest in Panama (Juan Diaz) and from premontane wet forest in Panama (Chimán). See Fig. 354.