Erect herb, 80-100 cm tall. Shoot with a decumbent, rooting base, octangular or subterete, bifariously pubescent or ultimately glabrescent. Leaves sometimes ternate, sessile, but contracted into a pseudo-petiole towards base, petiole 2-3 cm long, rugose along margin; blade lanceolate, 18-36 x 5.7-7 cm, caudate, glabrous or puberulous on lower surface on primary and secondary veins (13-14 pairs), cystoliths numerous, but sometimes difficult to see. Inflorescence spike-like racemes, latter in a large, rather dense terminal panicle, flowers borne secund; peduncle 12-18 cm long; axis about as long as, or slightly longer than peduncle, and like latter densely pubescent, branchlets puberulous; branchlets subtended by linear, 15-20 mm long leaves, other ones by filiform, to 12 mm long bracts; floral bracts and bracteoles triangular, 1.5 x 0.6 mm, glabrous, empty bracts much narrower, but nearly as long as fertile bracts; pedicels glabrous, 0.6 mm long. Calyx 5-lobed, subglabrous or puberulous, tube 1.2 mm long, lobes linear, 15-17 x 1 mm, tapering into a long point, 3-veined; corolla brick red, tubiform, 50-60 mm long, slightly curved, glabrous, lips 20 mm long, upper lip erect, bilobed, lobes less than 0.5 mm long, lower lip ± spreading, lobes 2.5-3 mm long; stamens inserted about 5 mm below mouth of corolla, filaments 23 mm long, glabrous, anthers with unequal thecae, longer theca 3 mm and shorter one 2.5 mm long, both about same height at base, obtuse apically, shortly apiculate at base; disk consisting of two ovoid-acuminate, glabrous lobes, much wider than ovary; ovary glandular at tip, style slightly puberulous at base, 50 mm long, stigma capitate. Capsule 14 mm long, glabrous, stipe 8 mm long, slightly sulcate at back, both seeds inserted at same height, retinacula with a distinct geniculum; seeds 2, fairly thick, ovoid, 3.2 x 2.8 mm, margin fringed with short, triangular scales (in unripe seeds these all turned to one side)
Can be grown by seedlings. Seeds needs soaking.