Short-lived perennial; stems square, somewhat scabrid, to c. 1 m tall. Lvs mostly petiolate, the uppermost sometimes subsessile. Lamina of lower lvs to c. 10 × 2.5 cm, lanceolate to oblong or rhomboid, with ± strigulose hairs scarcely swollen at base above and below, usually coarsely or deeply serrate; veins not impressed above; base attenuate; apex acute. Infl. loosely paniculate; spikes to c. 5 cm long at maximum flowering, hairy, elongating to c. 15 cm long at fruiting, slender; fls rather dense but soon becoming distant. Bracts ± = calyx at flowering, lanceolate, keeled, acuminate, ciliate. Calyx 2-3 mm long, glandular-hairy; teeth green, acute. Corolla tube > calyx, rather sparingly hairy outside; limb 2-3 mm diam., bluish or mauve, drying a similar colour. Nutlets c. 1.5 mm long, oblong, faintly ribbed dorsally, brown, finely white-papillate on flattened ventral surface.