Habracanthus macrochilus Lindau, Bull. Herb. Boiss. 5: 669. 1897. Type col- lected in the Province of Ocaña, Department of Norte de Santander, Colom- bia, in woods at 2,700 meters altitude by Schlim (No. 429). Photograph of type material of the Berlin Herbarium (Field Mus. No. 8890) in the U. S. National Herbarium.
Shrubby plants with terete pubescent branches; leaf blades oblong, pubescent, 4 to 7 cm. long, 2 to 3 cm. wide or smaller, the tip promi- nently acuminate, attenuate at base, the cystoliths striiform; petioles slender, 5 to 7 mm. long; panicles subdichotomous, terminal, longer than the leaves or axillary and shorter than the leaves and terminating the lateral branches, the lateral panicles lax and few-flowered, the terminal dense; calyx segments 12 mm. long, 1 mm. wide, unequal, becoming 18 to 19 mm. long and 1.5 mm. wide at maturity, glandular- pubescent; corolla purple, the tube 14 mm. long, 2 mm. wide at base, and 3 mm. wide at tip, the upper lip 28 mm. long and 4 mm. wide at base, narrowed to a subobtuse tip, the lower lip 28 mm. long, 10 mm. wide at middle, 4 mm. wide at tip and 3-toothed, the teeth 1.5 mm. long, obtuse; filaments 35 mm. long, inserted at tip of corolla tube and long-exserted; anthers 3.5 mm. long; style 50 mm. long, exserted; capsule 14 mm. long, 3 mm. wide, glabrous, the solid stipe 5 mm. long; seeds 4.
No specimens seen. Description compiled from the original. The specific epithet is from the Greek words μakpós, long, and xeixos, lip.
Lindau states in his discussion that his new species differs from the others known in the large lips of the corolla, and the long calyx segments, which, like the inflorescence, are coarsely pubescent.