Herbs up to 1 meter high or more; stems quadrangular, glabrous, the nodes more or less tumid; leaf blades lanceolate, up to 20 cm. long and 5.3 cm. wide, gradually narrowed from below middle to an acute more or less falcate tip, cuneate at base, one side attached to petiole about 5 mm. above the other, rather firm, shallowly and obscurely crenate, glabrous except the ciliate margins, their hairs curved, ascending, conspicuously septate, the cystoliths minute and obscure, the costa and lateral veins prominent beneath, less so above, the veinlets coarsely reticulate; petioles up to 3 mm. long, glabrous; panicles terminal, about 8 cm. long and 5 cm. broad, the nodes of the stems below the terminal panicle bearing for some distance small apparently abortive cymose inflorescences up to 2 cm. long, the branches of the terminal inflorescence subhelicoid, the entire panicle strictly glabrous, the pedicels 1.5 mm. long, 0.75 mm. thick, bearing minute subpunctiform cystoliths, the bracts sub- tending the branches of the inflorescence ovate, about 8 mm. long and 5 mm. wide, short-acuminate, the ultimate bracts lanceolate, about 4 mm. long and 1.25 mm. wide, acute; calyx 9 mm. long, glabrous, marked by slender linear cystoliths up to 0.2 mm. long, the calyces of the sterile axillary branches about 3 mm, long; corolla about 2 cm. long, glabrous, greenish-yellowish-white, the tips a sordid violet, the tube 3 mm. broad at mouth, slightly narrowed just below mouth, the upper lip linear, about 2 mm. wide, acute at tip, curled, the lower lip spreading, about 9 mm. long and 8 mm. wide, 3-lobed at tip, the lobes about 1 mm. long, obtuse; stamens exserted 15 mm. beyond the mouth of the corolla tube, glabrous, the anthers 4 mm. long and about 1 mm. broad, muticous at both ends; ovary glabrous; capsules not seen.
Type in the Herbarium of the Chicago Natural History Museum, No. 1273513, collected in open woods of Cajón de Pulido, Quebrada del Río Hacha, Cordillera Oriental, Comisaría del Caquetá, Colombia, 1,700 meters altitude, March 26, 1940, by J. Cuatrecasas (No. 8740).