Annual or short-lived perennial; stems to 80 cm tall, square, often scabrid on angles. Most lvs variously pinnatifid or pinnatisect (basal ones often deeply toothed), mostly petiolate (uppermost often sessile), sometimes scabrid, with hairs little swollen at base; lamina 3-6 × 1-4 cm, ± rhombic or oblanceolate; lobes oblong or ovate; veins not impressed above; base ± attenuate; apex obtuse to acute. Infl. very loosely paniculate; spikes to c. 15 cm long at maximum flowering, elongating to 25 cm at fruiting, slender, puberulent; fls soon becoming distant. Bracts 1/2-⅔ length of calyx, lanceolate to ovate, somewhat keeled, acuminate, hairy. Calyx 2-3 mm long, hairy; teeth acute, green or mauvish. Corolla tube > calyx, somewhat hairy outside; limb 4-5 mm diam., mauve or lavender, drying a similar colour. Nutlets c. 2 mm long, oblong, reddish brown, strongly ribbed dorsally, finely white-papillate and flattened ventrally.