Small shrub, 1.5 m tall, branched from a subligneous base. Stem green, quadrangular, erect, puberulous, wood soft. Petiole 10-35 mm long, subquadrangular, puberulous; blade herbaceous, ovate, 18-30 x 9-13 cm, acuminate at apex, attenuate at base, upper surface smooth, glabrous, lower surface sparsely puberulous, margin entire or faintly crenulate; primary vein sulcate on upper surface, convex on lower surface, secondary veins (10-12 pairs) reddish on lower surface. Inflorescence a reduced thyrsoid panicle of 4-10 cm long, branches opposite or subopposite, each bearing 1-3 flowers, rachis quadrangular, glabrous; floral bracts triangular, 2 x 1 mm; pedicels 6-12 mm long. Calyx green, 3.5-6 mm long, minutely puberulous and papillate, lobes narrowly triangular, 3-4 x 0.75-1 mm; corolla yellowish, (45-)50-70 mm long, papillate, tube curved inwards, 2-2.5 mm in diam. at base, apically 8-9 mm wide, somewhat contracted, lips 6-7 mm long, upper lip deeply 2-lobed, lobes of upper lip obovate, 5 x 4.5 mm, lower lip 3-lobed, lobes obovate, 6 x 5 mm; stamens exserted 5 mm beyond mouth of corolla tube, filaments minutely puberulous, connate from base to 2.5-8 mm, free part 8-9 and 12-13 mm long respectively, anthers 4 mm long, connective slightly expanded at apex; disk 2 mm high, conical projections 0.7-1 mm high; ovary 3-3.5 mm high, minutely puberulous, style 67 mm long, minutely puberulous, slightly exceeding stamens, stigma entire. Capsule clavate, 20-22 x 5 x 3 mm, minutely puberulous, apiculate, stipe 8-10 x 2.5 mm; retinacula curved, 4.5 mm long, erose; seeds 6, 3.5-4 mm in diam., glabrous except for margin fringed by appressed hygroscopic trichomes.
Southern America, Suriname present
Suriname and adjacent Brazil; 4 collections studied (SU: 3).