Terrestrial herb, 30-60 cm high. Stem fleshy, ascending, glabrous, sometimes puberulous at apex. Leaves equal or subequal in a pair; petiole (1-)6-12(-14) cm long, glabrous; blade chartaceous when dry, oblong-elliptic or oblong-lanceolate, 5-30 x 1-12 cm, margin subentire to crenate-serrate, apex acute, acuminate, or sometimes obtuse, base cuneate, rounded, or sometimes obliquely subcordate, above mostly glabrous or nearly so, sometimes strigose to subtomentose, below mostly glabrous or nearly so, sometimes sparsely pilose. Flowers mostly numerous and aggregated, umbellate or cymose; peduncle up to 1 cm long, minutely puberulous or glabrous; pedicel 0.7-3 cm long, practically glabrous. Calyx purple, lobes 4, erect, connate 1/3 their length, subequal, obliquely oblong-lanceolate, 1.2-3.3 x 0.3-0.8 cm, dorsal one mostly free, and slightly smaller, margin repand-serrate, apex acute, outside sparsely pilose or glabrous, inside sparsely pilose or glabrous; corolla oblique or horizontal in calyx, white or pale stramineous, sometimes with purple or purple-tipped lobes, (3-)4-6 cm long, tube trumpet-shaped, 2.5-4.7 cm long, base shortly spurred, 0.3-0.4 cm wide, middle not or hardly ventricose, slightly bent downwards, throat not or hardly contracted, 0.5-1.2 cm wide, outside hirsute, inside glabrous, limb 1.5-1.8 cm wide, lobes subequal, spreading, ventral lobe somewhat concave, suborbicular, 0.5-0.7 x 0.5-0.7 cm, margin entire; stamens included, inserted at base of corolla; ovary ovoid, 0.2-0.4 x 0.1-0.2 cm wide, hirsute, style 2-4 cm long, minutely puberulous or glabrous, stigma capitate. Mature capsule globose or nearly so, ca. 1 cm in diameter.
Endemic to the Guianas; > 100 collections studied (GU: 24; SU: 1; FG: 50).