Monographs Details: Habracanthus pilosus Leonard
Authority: Leonard, Emery C. 1958. The Acanthaceae of Colombia, III. Contr. U. S. Natl. Herb. 31: 323-781.
Description:Latin Diagnosis - Herba, caulibus debilibus, subteretibus, pilosis, pilis patulis, septatis; lamina foliorum lanceolata vel oblongo-elliptica, acuta vel breviter acuminata, (apice ipso subacuto), basi cuneata, membranacea, integra aliquanto dense pilosa et ciliata, pilis ascendentibus, costa et venis lateralibus inconspicuis; petioli pilosi; paniculae foliiferae laxae, floribus paucis, ramis simplicibus vel 1-furcatis, rhachis et rhachillis abundante pilosis, pilis patulis, acutis, conspicue septatis, pilis paucis in glandula parva conics terminantibus intermixtis; bracteae ultimae subulatae parvae, pilosae, apice recurvatae; calycis segments subulata, apice gracilia (apice ipso subobtuso), pilosa, pilis patulis septatis; corolla rubra, tubo deorsum piloso, pilis patulis, septatis, sursum glabro, labio superiors oblongs:), apice rotundato, labio inferiore ovato, 3-lobato, lobis ovatis, rotundatis; stamina exserta, glabra, antheris muticis et minute apiculatis; capsulae clavatae, glabrae; retinacula gracilia, recta, vel leviter curvata, apice rotundata, erosa; semina brunnea, levia vel leviter rugosa, basi obliqua.
Description - Herbs; stems weak, 1 to 2 mm. in diameter, subterete, pilose, the hairs spreading, up to 1.5 mm. long, septate; leaf blades lanceolate to oblong-elliptic, up to 6 cm. long and 2 cm. wide, acute to short-acuminate (the tip itself subacute), cuneate at base, thin, entire, rather densely pilose on both surfaces and ciliate, the hairs ascending, up to 1 mm. long, the costa and lateral veins (about 6 pairs) barely prominent beneath, obscure above; petioles up to 2 cm. long, pilose; panicles lax, few-flowered, leafy, the branches simple or once-forked, the rhachis and rachilla, rather copiously pilose, the hairs spreading, conspicuously septate, occasionally a few of the hairs terminating in a minute brownish conical gland, the leaflike bracts subtending the branches of the inflorescence 1 to 3 cm. long, 5 to 15 mm. wide; bracts subtending the flowers subulate, up to 2 mm. long and 0.25 mm. wide at base, pilose, the tips usually recurved, calyx 12 mm. long at maturity, rather densely pilose with septate spreading hairs up to 1.5 mm. long, the segments subulate, 1 mm. wide at base, gradually narrowed into a slender bluntish tip; corollas pale to dark red, 2 to 2.5 cm. long, the lower half rather sparingly pilose with septate hairs, these spreading and up to 0.5 mm. long, the upper half glabrous, the tube 1.5 mm. broad at base, narrowed to 1 mm. at 3 mm. above base, thence abruptly expanded to 5 mm., the lips erect or suberect, the upper lip oblong, 7 mm. long, 2 mm. wide near base, the tip rounded and entire, not contorted, the lower lip equaling the upper, ovate, 4.5 mm. wide, 3-lobed, the lobes ovate, about 3 mm. long, the middle one about 2 mm. wide at base, the lateral ones about 1 mm. wide, all rounded; stamens exserted about 1 cm. beyond the mouth of the corolla, glabrous, the anthers 4.5 mm. long and about 1 mm. broad, blunt and minutely apiculate; style slightly exceeding the stamens, the stigma minute; capsule clavate, 13 mm. long, about 5 mm. broad, 2 mm. thick, glabrous; retinacula 2 mm. long, slender, straight or slightly curved, the tips rounded, erose; seeds brown, 3 mm. long, 2 mm. wide, 0.75 mm. thick, smoothish or slightly roughened, oblique at base.
Discussion:Earl L. Core's No. 591 (US), collected in dense forest in the vicinity of Los Andes, on the Río Blanco, southeast of Guasca, "9,300 ft." altitude, April 19, 1944, is also of this species. The corollas of the holotype were stated to be pale red, and those of Core's No. 591 dark red.