Suffrutescent plants up to 1 meter high or more; stems simple or branched, the lower parts terete and glabrous, up to 2.5 cm. in diameter, the upper parts subquadrangular, moderately puberulous with curved hairs about 0.25 mm. long; leaf blades oblong-ovate, up to 9 cm. long and 5 cm. wide, acuminate, the tip often curved, narrowed at base, moderately firm, entire or undulate, the upper surface glabrous, the venation obscure, the cystoliths minute, blackish, 125μ long, the lower surface sparingly and inconspicuously hirtellous, the hairs ascending, about 100μ long, the costa and lateral veins (5 or 6 pairs) more promi- nent than above; petioles mostly 1 to 3 cm. long, 1 mm. thick, glabrous or puberulous with curved hairs; panicles up to 6 cm. long and 1.5 cm. broad, interrupted, the peduncle up to 4 cm. long, the lowermost internode about 2 cm. long, the others successively shorter toward tip, both peduncles and rachises puberulous with upwardly curved hairs up to 175μ long, the lowermost branches of the inflorescence subtended by leaves appreciably smaller than the stem-leaves, the uppermost flower clusters subtended by linear bracts up to 4.5 mm. long and 0.75 mm. wide at base, sparingly puberulous and ciliolate; bractlets subu- late, up to 2 mm. long and 0.5 mm. wide at base, acuminate, subglabrous, sparingly ciliolate; flowers usually about 4 to 8 to a cluster, the pedicels 1 mm. long, sparingly puberulous; calyx 4 mm. long, the segments linear, 3 to 4.75 mm. long, 0.5 mm. wide at base, acuminate, glabrous or sparingly ciliolate and hirtellous, the hairs up to 125μ long; corolla white, the tube narrow, 0.75 mm. broad at base, gradually enlarged to 1.5 mm. at mouth, the basal portion glabrous (1.5 mm.), the remainder of the tube densely glandular-papillose, the lobes oblong, about 4 mm. long and 1 to 1.5 mm. wide, subobtuse; stamens included, 3 mm. long, the filaments 1.5 mm. long, glabrous; staminodes minute, barely 0.25 mm. long; ovary glabrous; mature capsules not seen. Type in the herbarium of the New York Botanical Garden, collected on bank of stream in forest, El Umbo region, the vicinity of Mount Chapón in the western part of the Department of Boyacá, Colombia, "3,000 ft." altitude, September 19, 1932, by A. E. Lawrance (No. 441). Pseuderanthemum chaponense can be easily recognized by the slen- der, densely glandular-papillose corolla tube, and narrow corolla lobes.