Shrubs up to 2 m tall, erect. Stems stout, scarcely branched, glabrous, often with stipule like spines at nodes. Petiole 3-6 mm, thick, glabrous; leaf blade oblong to oblong-lanceolate, 6-14 × 2-5 cm, glabrous, secondary veins 5-7 on each side of midvein, base cuneate, margin pinnatifid and with few large spines, serrate, or subentire, apex truncate. Spikes terminal, to 16.5 cm; bracts broadly ovate, 7-8 mm, caducous; bracteoles ovate, ca. 5 mm, leathery.

Calyx posterior and anterior lobes 1-1.3 cm, margin scarious and sometimes crispate, apex emarginate; lateral lobes ovate, ca. 1 cm, margin entire. Corolla white [bluish to pinkish], 3-4 cm; tube ca. 6 mm; lip obovate, 2.2-3 cm, thinly leathery, outside with soft trichomes, apex 3-cleft. Stamens equal; filaments ca. 1.5 cm; anther theca with a line of trichomes on both sides of the suture. Style ca. 2.2 cm. Capsule 2.5-3 cm. Seeds light yellow, reniform. Fl. Feb-Mar, fr. Aug-Sep. 2n = 44, 48.