Lianas without interpetiolar glandular fields; pseudostipules small and ± subulate or subfoliaceous. Leaves 3-foliolate or the terminal leaflet replaced with a simple tendril. Inflorescence a raceme or racemose-branched panicle, axillary or terminal, bracteate and bracteolate. Calyx cupular, bilabiate to ± truncate, usually with conspicuous plate-shaped glands; corolla yellow, tubular-funnel-shaped to tubular-campanulate, usually pubescent outside. Anthers glabrous, the thecae straight, divaricate or ± divergent. Ovary narrowly cylindric, lepidote to puberulous; ovules 2-seriate in each locule; disk pulviniform. Fruit an oblong capsule, the valves parallel to the septum, slightly or not at all compressed, woody, often with prominent lenticels, the central vein inconspicuous. Seeds 2-winged or ± wingless, the seed body relatively thick and corky, the wings when present poorly demarcated, hyaline only at apex.
Continental Neotropics from Mexico to Argentina plus Trinidad-Tobago and perhaps Grenada; 35 species, 4 in Venezuela, all in the flora area.
1. Capsule valves concave, the fruit conspicuously 4-winged; calyx with conspicuous whitish marginal fringe; leaflets without cartilaginous margins; flowers orangish yellow .... A. purpurascens
1. Capsule valves convex, the fruit unwinged; calyx without whitish marginal fringe or with a very tenuous one; leaflets with cartilaginous margins; flowers lemon-yellow ..... 2
2(1). Corolla tube glabrous outside; anther connective not prolonged; calyx > 13 mm long, truncate; fruit drying black, the surface macroscopically smooth ..... A. impressum
2. Corolla tube pubescent outside; anther connective prolonged, apiculate; calyx less than 13 mm long, bilabiate; fruit drying grayish or tannish, the surface macroscopically rough ..... 3
3(2). Fruit ellipsoid-globose, 4-valved; ovary 1-2 mm long, cylindric with tetragonal apex; lower surface of leaflets usually puberulous ..... A. apurense
3. Fruit oblong, 2-valved; ovary 2.5-3.5 cm long, cylindric narrowing gradually to style base; lower surface of leaflets never puberulous ..... A. inundatum
Adenocalymna apurense (H.B.K.) Sandwith, Lilloa 3: 461. 1938. -Bignonia apurensis H.B.K., Nov. Gen. Sp. (quarto ed.) 3: 138. 1818 .
Liana with water-dispersed seeds. Gallery, secondary, and semideciduous lowland forests, 50-200 m; northern Bolívar (especially along Río Orinoco and Río Cuyuní). Apure. Fig. 349.
Adenocalymna impressum (Rusby) Sandwith, Recueil Trav. Bot. Néerl. 34: 212. 1937. -Bignonia impressa Rusby, Mem. Torrey Bot. Club 6: 100. 1896.
Liana. Gallery, evergreen lowland, and upland forests, 50-1000 m; Bolívar (Río Caura basin), Amazonas (upper Río Orinoco, lower Río Ventuari). Apure; French Guiana, Amazonian Peru, Brazil, and Bolivia. Fig. 351.
The glabrous corolla of Adenocalymna impressum is unique among Venezuelan species.
Adenocalymna inundatum Mart. ex A. DC., Prodr. 9: 201. 1845.
Mexico, Central America, Grenada, Trinidad-Tobago, Venezuela, Guyana, Suriname, French Guiana, Brazil; 2 varieties, both in Venezuela, 1 of these in the flora area.
A. inundatum var. surinamense Bureau & K. Schum. in Mart., Fl. Bras. 8(2): 94. 1896.
Liana. Gallery forests, 50-200 m; Bolívar (middle Río Caura), Amazonas (La Esmeralda). Guyana, Suriname, French Guiana, Peru, Brazil. Fig. 350.
This variety is distinguished from var. inundatum by having thick, corky, wingless seeds. It is possible that var. inundatum, which reaches Trinidad-Tobago and northern Venezuela in the southern part of its range, may eventually be found in the northernmost part of the flora area.
Adenocalymna purpurascens Rusby, Desc. S. Amer. Pl. 121. 1920.
Liana, easily characterized by the unusual thick-winged fruit. Evergreen lowland and secondary forests, 50-300 m; Delta Amacuro (lower Río Orinoco, Serranía de Imataca), northern Bolívar, northwestern Amazonas. Guyana, Amazonian Ecuador, Peru, Brazil, and Bolivia. Fig. 352.