Hairy, prostrate or semi-prostrate annual; stems many, decumbent, arising from near base, freely rooting at nodes, up to c. 70 cm long. Petioles to c. 1 cm long, usually shorter. Lamina 0.6-2.5 × 0.5-2 cm, ovate or broad-ovate, hairy, coarsely and irregularly crenate-serrate or serrate; base broad-cuneate, truncate or subcordate; apex obtuse to rounded. Fls axillary, solitary in axils of lvs similar to vegetative lvs; pedicels slender, > subtending lvs, to c. 4 cm long at fruiting, densely hairy. Calyx 5-7 mm long; lobes ovate-lanceolate to ± elliptic, ciliate, broad-cuneate to rounded at base, obtuse at apex. Corolla 10-15 mm diam.; 3 lobes bright blue; lowest lobe narrower, white to pale blue. Capsule c. 8 mm wide; lobes rounded, strongly divergent, sharply keeled, ± hairy. Seed broad-ellipsoid, strongly concave on 1 side, tuberculately ridged.