Slender shrub; stems quadrangular, glabrous below, the upper portions minutely and upwardly strigose, the hairs yellowish, up to 0.11 mm. long; leaf blades oblong-ovate to elliptic, up to 20 cm. long and 10.5 cm. wide, acute or short-acuminate, acute, obtuse or rounded at base, firm and somewhat chartaceous, both surfaces glabrous or the costa beneath minutely and inconspicuously strigose, the cystoliths numerous and conspicuous; petioles up to 5.5 cm. long and 2.25 mm. thick, glabrous or sparingly and minutely strigose; spikes one to several, terminal, up to 8 cm, long and 1 cm. broad, densely flowered, the peduncles up to 4 cm. long, minutely strigose to subglabrous, the rachis densely brown-puberulous with hairs up to 0.2 mm. or occa- sionally longer, the flowers secund; sterile bracts opposite the flowers closely appressed to the rachis, ovate, 3 mm. long, 1.5 mm. wide near base, acute, strongly 5- to 7-nerved, puberulous like the rachis; bracts subtending the flowers triangular, 3 mm. long, 1.5 mm. wide at base, acute, striate nerved, minutely hirsute and ciliolate; bractlets triangu- lar, 1.75 mm. long, 0.5 mm. wide at base, acute, ciliate, the basal hairs up to 0.5 mm. long, otherwise glabrous or nearly so, the cystoliths minute but conspicuous on both bracts and bractlets; calyx 1 cm. long, the segments subulate, 6-8 mm. long, 0.5-1 mm. wide, acuminate, striate, finely and sparingly pubescent and ciliate, the hairs up to 0.25 mm. long; corolla 3 cm. long, rather densely pubescent with hairs variously curved and about 0.16 mm. long, purple with light lines on the medial inner surface of lips and throat, the corolla tube 2 mm.  broad at base, narrowed to 1.5 mm. at 4 mm. above base, thence gradually enlarged to 5 mm. at mouth, the upper lip erect, triangular, about 5 mm. wide at base, gradually narrowed to a slender tip, the lower lip spreading, oblong with narrowed base, 6.5 mm. wide, truncate at tip and 3-lobed, the lobes rounded, 1 mm. long, the middle one 2.5 mm. wide, the lateral ones 2 mm. wide; stamens almost reaching the tip of the upper lip of the corolla, the filaments bearing a row of minute glandular hairs, the anthers 3 mm. long and 0.75 mm. thick,  the lobes superposed, 1.5 mm. long, vertically attached to the con- nective, the lower lobe terminating in a blunt white spur 0.5 mm. long; ovary pubescent at tip; capsules not seen.
Type in the U. S. National Herbarium, No. 1995081, collected along a stream in wet forest southeast of Chigorodo, 40 km. south of Turbo, Department of Antioquia, Colombia, 50 meters altitude, April 15, 1945, by Oscar Haught (No. 4564).
ANTIOQUIA: Dense damp forests between Río Guapá and Río León, 100 meters altitude, March 18, 1948, Eduardo Ruiz Landa, Rafael Rivera, & Fred A. Barkley 18C.430 (US). Trail through rain forests near Villa Arteaga, 150 meters altitude, December 6, 1948, F. López & M. J. Sanchez 41 (US); August 4 to 8, 1947, W. H. Hodge 6978 (US).
The dense spikes, with small triangular bracts, the slender calyx segments, and the relatively large, papery, conspicuously veiny leaf blades covered with cystoliths are the distinguishing characteristics of J. phlebophylla. The specific epithet is from the Greek λė, vein, and φύλλον, leaf.