Herbs up to 25 cm. high, ascending; stems subquadrangular, minutely and finely retrorsely strigose, the hairs up to 0.11 mm. long; leaf blades ovate, up to 9 cm. long and 4.8 cm. wide, short-acuminate (the tip itself blunt), acute to obtuse at base, rather firm, entire, glabrous on both surfaces except the strigose costa and lateral veins (8 or 9 pairs) of the lower surface, the cystoliths slender, up to 0.24 mm. long, rather obscure; petioles up to 1 cm. long, sparingly strigose or hirtellous, the hairs up to 0.16 mm. long; flowers borne in trifurcate spikes up to 7 cm. long and 5 mm. broad, the common peduncle 10.5 cm. long, subquadrangular, 1.5 mm. thick, hirsute, the hairs ascending, up to 0.32 mm. long, septate, the secondary peduncle of central spike 17 mm. long, those of the lateral ones 15 mm. long, all hirsute, the bracts subtending the 3 spikes lanceolate, 7 mm. long, 2.5 mm. wide, carinate, closely penninerved, hirsute, the hairs mostly marginal and costal; bracts subtending the flowers narrowly ovate, subacute, 4.5 mm. long, 1.25 mm. wide at base, sparingly hirtellous, the hairs mostly marginal, up to 0.19 mm. long, spreading or ascending, straight or nearly so, the costa and lateral nerves (2 or 3 pairs) prominent; bract- lets narrowly triangular, 4 mm. long, 0.75 mm. wide at base, sparingly hirtellous, acute, costa and lateral nerves 1 or 2 pairs, prominent; calyx 7 mm. long, hirtellous and puberulous, the longer hairs eglandu- lar, slightly curved, up to 0.19 mm, long, the smaller hairs straight, spreading, up to 0.06 mm. long, tipped by small spherical glands, the costa and the 2 pairs of lateral nerves prominent; corolla 15 mm. long, white, minutely hirtellous, the hairs straight or slightly curved, more or less spreading, the tube 6 mm. long, 2 mm. broad at base, narrowed at 3 mm. above base to 1.5 mm., thence enlarged to 2 mm. at throat, the upper lip erect, oblong, about 9 mm. long, 3 mm. wide near base, acutish at tip, the lower lip more or less spreading, about 7 mm. long, cuneate, 2 mm. wide at base of the lobes, these suborbicular, about 1.25 mm. in diameter, the stamens reaching the tip of and partly lying in the upper lip of the corolla, declinate, the filaments glabrous except at base, here retrorsely hirsute, the hairs about 0.16 mm. long, straight, slender; anthers 2.5 mm. long and 0.5 mm. thick, the cells superposed, vertically attached to the connective, the lower cell terminating in a blunt tail 0.5 mm. long; capsules clavate, about 1 cm, long, 2 mm. broad, 1.75 mm. thick, both hirtellous and puberulous, the longer hairs rigid, eglandular, spreading or retrorse toward base and ascend- ing toward tip, up to 0.13 mm. long, the smaller hairs spreading, up to 0.06 mm. long, glandular; retinacula 4, about 2 mm. long, white, truncate, erose.
Type in the U. S. National Herbarium, No. 1772180, collected in dense forests at Istmina, on the Río San Juan, Intendencia of Chocó, Colombia, about 75 meters altitude, April 29, 1939, by E. P. Killip (No. 35469).
Cuoco: Río San Juan, vicinity of Palestina, 0-40 meters, May 29, 1946' Cuatrecasas 21428 (Valle).
Justicia killipii is closely related to J. sterea Leonard but can be separated by its smaller size, the more ovate-shaped leaves and the much larger spikes. The plants of J. sterea often exceed 70 cm. in height, thus being at least twice as high as those of J. killipii; their elliptic leaves are up to 13.5 cm. long and 5.5 cm. wide instead of only 9 cm. long and 4.8 cm. wide, and their spikes are only 3 cm. long instead of 7 cm.