Glab. herb with erect to spreading stems and branches, up to ± 4 dm. tall, us. less; branchlets grooved and angled, ± narrowly winged. Lvs of rather diverse form, on flat petioles up to ± 10 mm. long. Lamina entire to obscurely to distinctly toothed, fleshy to submembr.; of lower lvs broad- to oblong-ovate, narrowed into winged decurrent petiole, (10)-20-40-(50) × (5)-8-15 mm.; of mid lvs subsessile, narrow-oblong to lanceolate, ± 20-50 × 5-10 mm.; of upper and subfloral lvs sessile, lanceolate to linear, 10-30 × 1-5 mm. On many plants the lf-shape is more constant. Fls ± 5-10 mm. long, on very slender peduncles up to ± 10 mm. long, occ. confined to uppermost part of branchlets. Receptacle cylindric, grooved. Calyx-lobes short, triangular to linear, acute to acuminate. Corolla white to pale blue, 6-7 mm. long; lobes linear to oblong, acute. Capsule ± 8-12 mm. long, narrow-clavate.

n = 7

2n = 14

Herb to c. 40 cm long, usually much less, with vegetative parts glabrous; sap clear. Stems erect to widespreading or prostrate, not usually rooting at nodes; branchlets narrowly winged, grooved. Lvs very variable; petioles flat, to c. 10 mm long. Lamina submembranous to ± succulent, entire or variously toothed; lamina of lower lvs (10)-15-40-(50) × (5)-8-20 mm, broad-ovate to oblong-ovate, sometimes purplish, decurrent at base. Lvs becoming narrower and petioles shorter above; uppermost lvs sessile, narrow, linear to lanceolate or spathulate, 10-60 × 1-5 mm (sometimes lf shape varies little from base to shoot apex). Peduncles 2-5-(7) mm long, usually puberulent. Calyx lobes 0.9-1.5 mm long, linear to triangular, acute or acuminate. Corolla 6-10 mm long, white, pale blue (often deeper blue on lower lip), less commonly pale pink; lobes of lower lip 5-8 mm long, linear to oblong. Capsule 6-12 mm long, narrow-clavate to almost cylindric.