Erect herb or shrub; stem stout, 4-angled with concave faces, finely puberulous, as thick as fingers; leaves broadly ovate, acute at apex, coarsely crenate, slender, membranous, puberulous; petiole slender, winged in the upper part; flowers scarlet in axillary, globose, 5-10 cm in diameter, whorls distant; floral leaves deflexed lanceolate; pedicels very short; bracts linear, slender, deflexed, spine-tipped; calyx 8-10, ribbed, 10 nerved, teeth unequal, spine-tipped, upper lip large, prominent, rigid, lower lip with 3, erect or recurved teeth, throat glabrous, tube incurved, puberulous below, densely hispid above with long hairs; corolla tubular, orange-red, glabrous; upper lip long, concave, tube slender, hairy inside, lower one small, concave with midlobe largest; stamens 4, exserted, lower pair longest, anther 2 cells divaricate, subconfluent; disc unequal; ovary 4-partite, style subulate, upper lobe very short, stigma unequally, shortly 2 fid; nutlets-4, oblong-obovoid, obtuse or truncate, glabrous.