Straggling or prostrate annual herb 10–60 cm. long with bright pale yellow green stems and foliage; stems branched or unbranched, square with angles slightly to distinctly winged, glabrous or with sparse to fairly dense short hairs on the angles or stems hairy all over.. Leaf-blades often red margined, elliptic, 1.2–5 cm. long, 0.8–2.9 cm. wide, acute at the apex, cuneate at the base, pubescent or ± scabrid above with tubercle-based hairs, pubescent beneath or almost glabrescent all over save for the scabrid margins; petiole 0.5–3 mm. long; stipule-sheath 1.5 mm. long, with 5–9 setae 1.5–3.5 mm. long.. Flowers in axillary clusters ± 8 mm. wide.. Calyx-tube pubescent, obconic, 2.5 mm. long; lobes 4, oblong to lanceolate, 1.2–2 mm. long.. Corolla whitish, blue or pink; tube funnel-shaped, 5 mm. long; lobes ovate-triangular, 1.5 mm. long and wide.. Filaments exserted ± 1 mm.. Style exserted 2 mm.; stigma-lobes linear, 1 mm. long.. Capsule ellipsoid or subglobose, 2.5–3 mm. long, wrinkled, hairy.. Seeds yellow brown, ellipsoid, 2–2.8 mm. long, 1.3–1.7 mm. wide, 0.8–1 mm. thick, reticulate-rugulose, with a deep wide ventral excavation.. Fig. 50/22, p. 342.