Erect or ascending herbs up to 40 cm. high; stems subquadrangular, glabrous or the upper portions puberulous in two lines, the hairs curved and subappressed, up to 0.15 mm. long, the nodes of the stems swollen; leaf blades up to 9 cm. long and 2.7 cm. wide, ovate to broadly lanceolate, short-acuminate (the tip itself blunt), acute to obtuse at base, thin, entire or undulate, glabrous or the costa sparingly hirtel- lous, this and the lateral veins (about 5 pairs) faint, the cystoliths numerous and conspicuous under a lens, up to 0.2 mm. long; petioles slender, 5 to 10 mm. long, glabrous or sparingly puberulous, the cystoliths numerous, minute and parallel; spikes slender, terminal and axillary, 2 to 4 cm. long, 2 to 4 mm. wide, the peduncles slender, 5 to 10 mm. long, subquadrangular, flattened toward tip, hirtellous in 2 lines, the hairs up to 0.5 mm. long, the rachis flattened, glabrous or sparingly hirtellous, lowermost internodes 5 mm. long, successively shorter toward the tip of the spike; bracts lance-subulate, 3 mm. long, 0.75 mm. wide at base, carinate, glabrous, the costa prominent; bractlets lance-subulate, 2 mm. long, 0.25 mm. wide near base, gla- brous; calyx 2.75 mm. long, the segments 4, lanceolate, 0.5 mm. wide near base, narrowed to a slender tip, glabrous, or sparingly ciliolate, the costa obscure; corolla white externally, purple within, glabrous or the inner surface of the lips puberulous, 12-14 mm. long, the tube 1.5 mm. broad at base, subcylindrical, 2 mm. broad at throat, the lips subequal, 3.5 mm. long, the upper lip erect, ovate, 2 mm. wide at base, rounded at tip, the lower lip more or less spreading, 3-lobed, the lobes suborbicular, about 1.5 mm. wide, rounded; stamens barely exserted, the filaments slender, flattened, glabrous, the anther lobes attached to a flattened connective 0.75 mm. wide, the upper cell oblique, 0.75 mm. long, the lower cell 0.5 mm. long, attached more or less vertically, both glabrous; capsules clavate, 12 mm. long, 2.5 mm. broad, 1.25 mm. thick, glabrous. Type in the U. S. National Herbarium, No. 1989433, collected alone the Loretoyacu River, in the "trapecio amazónico," Intendencia of Amazonas, Colombia, about 100 meters altitude, September 1946, by Richard Evans Schultes and George A. Black (No. 8317). Schultes & Black No. 8697, collected in the same general region, is also of this species.