Perennial herb, basal part of stem creeping and rooting, apical part erect, to 20 cm tall, tomentose from long many-celled downwardly directed hairs. Leaves opposite, beneath paler with dark venation; petiole 0.3–2 cm long; lamina obovate, largest 8–14.5≈4–7 cm, apex subacute to rounded, base subcordate, subglabrous to densely pubescent, densest on veins. Spike terminal, solitary, sessile, 3–8(–12) cm long; axis puberulous; flowers subopposite; fertile bracts imbricate, greyish or straw-coloured to green, lanceolate to narrowly ovate, 14–18≈3–6 mm, acute and terminating in a straight mucro up to 1 mm long, glabrous to finely puberulous, serrulate in upper part, with many parallel veins; bracteoles linear-lanceolate, ± 1 cm long, finely puberulous. Sepals lanceolate, 5.5–7 mm long, acute, finely serrulate near tip, glabrous or puberulous near tip. Corolla pale blue, pale violet, pale mauve or white with purple markings in throat; tube 2.5–3 cm long; lobes in upper lip ± 1 cm long, in lower lip 1.2–1.5 cm long. Style with 2 broad fimbriate lobes, the upper longer. Capsule 4-seeded, 9–11 mm long. Seed 3–3.5 mm long, irregularly triangular in outline, tuberculate. Fig. 21, 1–3, p. 135.
