Vine with woody rootstock; stem sarmentose; branchlets glabrous; pseudostipules lacking. Leaves: petiole 2-3 cm long; blade triangular to sagittate, 6-13 x 4-8 cm, glabrous, greyishshining above, beneath, apex acute to rounded, base slightly to strongly cordate; venation pedate. Inflorescence axillary or flower solitary; pedicels 2-5 cm long. Flowers: ovary 0.7-15 mm long; perianth pale brown with yellow veins outside, glabrous; utricle ovoid, 10-13 x 6-8 mm; tube cylindric, 1-1.5 cm; limb funnel-shaped, about 1.5 in diam., lobe unique, superior, erect, 1-1.5 cm long, yellow at base, distal part violet brown, with fleshy, dark purple fimbriae, ovoid, apex acuminate. Fruit (from Caribbean collections) 3-3.5 cm long, glabrous; seeds 3-4 mm long.
Caribbean region present, Southern America: Bolivia (Bolivia present)
Widely distributed in the Caribbean region, W to Brazil and S to Bolivia; more than 30 collections studied (GU: 4; SU: 1; FG: 2).
A recent collection (Cremers and Crozier 14677), that came in after this treatment was completed, does not match with any of the species treated. It could belong to
A. disticha Masters which had not yet been recorded from the Guianas area (F. Gonzalez, pers. comm.). F. Gonzalez, who is carrying out a monographic study of the genus Aristolochia, also has informed us that two other specimens from the Guianas (Benoist 891 and Melinon 428) cited in this treatment under A. rugosa would fit better in A. disticha. Both species are very close, but the surface of the leaf of A. disticha is smooth and the flowers are arranged in short distichous racemes, while A. rugosa has rugose leaves and axillary flowers. The authors express their acknowledgments to F. Gonzalez for providing this information.