Annual or short–lived perennial, decumbent to erect herb, 5–60 cm. tall. Stem angular, narrowly winged, glabrous or pubescent on the wings with rather rigid hairs. Leaves (5)20–70 x 2–10(17) mm., crenate to serrate or subpinnatifid, the upper linear to lanceolate, the lower linear to spathulate or suborbicular, acute to obtuse at the apex, sessile or narrowing below into a petiole–like base or an up to 7 mm. long petiole, glabrous or lower leaves ± pubescent. Flowers in lax racemes; pedicels 5–50 mm. long, glabrous or papillose to short pubescent; bracts similar to upper stem leaves, shorter to longer than the pedicels; bracteoles c. 0·4–1·6 mm. long, linear, at or near the base of the pedicel. Hypanthium narrowly obconical to obovoid, 8–10–nerved, glabrous or papillose to short pubescent. Calyx–lobes narrowly triangular, erect or spreading, 1·2–6 mm. long, with one to three pairs of teeth at the margin or entire, glabrous or ciliate to pubescent. Corolla 8–15 mm. long, blue, mauve or white, with two bumps in the mouth of the tube, split to 0·3·1·5 mm. from the base on the back, papillose on the inside of the tube, glabrous or pubescent on the outside. Filaments linear, puberulous at the base or ± along their entire length, attached to the corolla–tube at the base. Anther–tube (1·2)2–2·4 mm. long, ± pubescent on the back of the upper thecae, or glabrous, the two lower anthers each with a tuft of hairs and a hyaline appendage at the apex. Ovary subinferior. Capsule 8–10–nerved with 2 valves 1–1·5 mm. long, inferior part of capsule 3–7 mm. long. Seeds elliptic to broadly elliptic in outline, somewhat compressed, 0·35–0·5 mm. long, very finely striate, brown.
