Lianas, the branchlets terete; interpetiolar glandular fields present or absent; pseudostipules small, ovate to lanceolate; juvenile plants distinctive, growing closely appressed against a supporting tree and climbing by means of recurved trifid tendrils. Leaves 2-foliolate, sometimes with a trifid, hooked tendril. Inflorescence a contracted axillary few- to several-flowered cyme or panicle, often reduced to a single flower. Calyx membranous, loosely campanulate, truncate to subspathaceous, often irregularly lobed; corolla yellow, tubular-campanulate, glabrous outside. Anthers glabrous, the thecae straight, divaricate. Ovary linear-oblong, minutely lepidote to subpuberulous or glabrate; ovules 2-4-seriate in each locule; disk ± annular-pulvinate. Fruit a narrow, linear, compressed capsule, the valves parallel to the septum, smooth, the midline thin, slightly raised. Seeds thin, 2-winged, the wings not sharply demarcated from seed body, short and brown or longer and irregularly hyaline at tips.
Mexico and the West Indies to northern Argentina; 4 species, 2 in Venezuela, both in the flora area.
1. Calyx subspathaceously split, often with an incurved apicule; leaflets long-acuminate; pseudostipules subulate-lanceolate; interpetiolar glandular fields conspicuous; seeds with short wings, shiny and dark blackish brown; swamps ..... M. uncata
1. Calyx truncate or subtruncate, without an apicule; leaflets acute or short-acuminate; pseudostipules ± ovate, usually striate; interpetiolar glandular fields absent or small and inconspicuous; seeds with wings longer and irregularly hyaline at tip; well-drained sites ..... M. unguis-cati
Macfadyena uncata (Andrews) Sprague & Sandwith, Recueil Trav. Bot. Néerl. 34: 215. 1937. -Bignonia uncata Andrews, Bot. Repos. t. 530. 1808. -Bejuco murciélago.
Vine or liana. Swamps, riverside forests, 50-300 m; Delta Amacuro (Río Acure), northern Bolívar, Amazonas (Río Mawarinuma, Río Parucito basin). Apure, Barinas, Falcón, Guárico, Miranda, Monagas, Sucre, Yaracuy, Zulia; southern Mexico to northern Argentina. Fig. 385.
Macfadyena unguis-cati (L.) A.H. Gentry, Brittonia 25: 236. 1973. -Bignonia unguis-cati L., Sp. Pl. 623. 1753. -Bejuco aguadero, Bejuco murciélago.
Liana. Seasonally moist or wet, nonflooded, evergreen lowland forests, 50-300 m; Delta Amacuro (Serranía de Imataca), northern Bolívar, Amazonas (near Puerto Ayacucho). Widespread elsewhere in Venezuela; Mexico and the West Indies to northern Argentina. Fig. 386.