Perennial or shrubby herb with several unbranched or sparsely branched stems from woody rootstock; stems erect (rarely scrambling or decumbent), to 1.5 m tall, sparsely to densely uniformly puberulous (rarely sericeous), in subsp.verticillaris usually also with stalked capitate glands and long pilose hairs. Mature leaves ovate to elliptic or narrowly so (rarely obovate), largest 3–10.5≈0.9–3.2(–4) cm, apex subacuminate to rounded, beneath uniformly puberulous or denser along veins or along veins only, above uniformly puberulous or sparsely so. Flowers in condensed axillary 3–15-flowered cymes, usually 2 cymes per axil or solitary towards apex, cymes often congested towards tip of stems; peduncle and branches up to 3(–5) mm long, indumentum as stems; outer bracts elliptic or narrowly so, up to 2 cm long, sometimes with capitate glands; inner bracts and bracteoles linear to lanceolate, up to 1 cm long. Calyx sparsely to densely puberulous with non-glandular hairs (subsp.trichocalyx) or viscid glandular-puberulous (subsp.verticillaris), also with or without long pilose non-glandular hairs, (8–)10–19(–21 in fruit) mm long; teeth (4–)5–12(–14 in fruit) mm long, same length or longer than tube. Corolla distinctly 2-lipped, pale mauve to mauve, pale purple to purple, blue to bluish purple (rarely white), usually with darker lines or spots on lower lip and in throat, palate distinctly bullate between veins, puberulent and with scattered capitate glands, 14–29(–37) mm long of which the linear tube 5–12(–14) mm, the throat 3–9(–12) mm and the limb 4–10(–13) mm, throat same length or 1–2 mm shorter than limb; lobes oblong, erect in upper lip, deflexed in lower. Free part of filaments 2–8 mm long, hairy near base, glabrous upwards or hairy to apex; anthers pale violet or mauve, 1–3 mm long, spurs ± 1/4–1/2 mm long often with 1–2 small subsidiary spurs or main spurs branched. Capsule 8–12 mm long. Seed 2–3 mm long. Fig. 29, p. 193.