Shrub, 1 m tall, branched from a subligneous base. Stem erect, quadrangular, branching, glabrous. Petioles 5-15 mm long, canaliculate, puberulous; blade elliptic, 15-16 x 4.5-5 cm, firm, acuminate at apex, attenuate at base, margin faintly and irregularly crenate, upper surface smooth, glabrous, drying olive green, lower surface densely pilose and purplish; primary vein sulcate on upper surface, convex on lower surface, secondary veins ca. 8 pairs or more, convex on both surfaces. Inflorescence cymose, terminal and axillary, once or twice dichasially branched; peduncle 1.5-6 cm long, conspicuously glandular pilose, trichomesyellowish; basal bracts linear, to 10 mm long, others smaller, glandular pilose; pedicel of central flower 3 mm long, glandular pilose; bracteoles subulate, 2.5-3 x 0.4-0.5 mm, glandular pilose. Calyx deeply 5-lobed, lobes linear, 10-14 x 0.5 mm, conspicuously glandular pilose, trichomes yellowish; corolla white, 35-45 mm long, glabrous except upper part of tube minutely pilose, limb suberect, lobes obovate, 7-8 x 6-8 mm, retuse apically; stamens included, anthers 3 mm long; ovary and style puberulent. Capsule narrowly ovoid, 15 x 4 x 3 mm, pubescent, apiculate and tinged with red apically, stipe 5 mm long; seeds 2.5 x 2 mm, dark brown, glabrous, margin fringed by hygroscopic trichomes.
granitic outcrops in French Guiana present
Known only from granitic outcrops in French Guiana at ca. 400 m elev.; 3 collections studied all from the vicinity of Saül, Tracé Carbet Mais, de Granville 3015 (US) and Mt. Galbao, de Granville 2412 (US).