Erect branched herbs up to 1 meter high; stems subquadrangular, the angles minutely acute, glabrous or sparingly pubescent, the hairs retrorsely curved, about 0.16 mm. long; leaf blades ovate, up to 6 cm. long and 2.5 cm. wide, short-acuminate (the tip itself obtuse), narrowed at base, firm, entire or undulate, both surfaces sparingly hirtellous, the hairs of the lower surface confined chiefly to the costa and lateral veins, the hairs up to 0.3 mm. long, more or less curved, the venation (lateral veins 5 to 7 pairs) prominent beneath, less so above, the cystoliths obscure or lacking; petioles up to 5 mm. long and 1 mm. thick, sparingly hirtellous; flowers (1 to 3) borne in small axillary panicles up to 3 cm. long, the peduncles up to 11 mm. long, the sec- ondary peduncles up to 8 mm. long, both primary and secondary peduncles sparingly hirtellous with more or less curved hairs, subquadrangular, the angles acute; bracts subtending the secondary peduncles leaflike, ovate, 4 mm. long, 2 mm. wide, subacute at tip, narrowed at base, sparingly hirtellous, the petioles about 1 mm. long; bracts subtending the flowers oblong, 1.5 mm. long, about 0.5 mm. wide, acute, ciliate, the flat surfaces glabrous or nearly so; calyx 1 cm. long, the segments 5, oblong, 8.5 mm. long, 1.5 mm. wide, acute, conspicuously 3-nerved, the outer surface glabrous or bearing a few small hairs near or on the margins, the inner surface sparingly and minutely hirtellous; corollas, from base to tips of the lips, 4.4 cm.
long, puberulous except the glabrous basal portion, yellowish-red, the tube 2.5 mm. broad at base, expanding at 8 mm. above base to 4 mm., the upper expanded portion cylindric, the upper lip narrowly ovate, 2 cm. long, 7 mm. wide at base, thence gradually narrowed to a small 2-lobed tip, the lobes about 0.75 mm. long and 0.5 mm. wide, rounded, the lower lip ascending, 18 mm. long, 6.5 mm. wide just above middle, the basal portion cuneate, the tip rounded and minutely 3-lobed, the lobes 0.5 mm. long and 0.75 mm. wide, rounded; stamens exserted about 13 mm. beyond the mouth of the corolla; anther lobes superposed, 3 mm. long, 1 mm. thick, both lobes short-caudate at base; ovary glabrous; capsules not seen.
Type in the Kew Herbarium, collected in border of forest at La Obrell, between Ocaña and Pamplona, Department of Norte de San- tander, March 25, 1879, by W. Kalbreyer (No. 1043).
Justicia jacobinioides may be related to J. aurantiaca. The two species have similar calyces and anthers, and the corollas are of the same general shape. The corollas of J. aurantiaca, however, are strictly glabrous instead of rather densely puberulous and the leaf blades are much larger, thinner, and glabrous. Moreover, the inflorescence of J. jacobinioides is axillary, whereas in J. aurantiaca it is terminal and more compound.