Glab. herb with pale yellow acrid sap. Roots ∞, rather stout, far-spreading; stems and branches tough, ascending through rock-debris; branchlets appearing above surface, up to ± 10 cm. long. Lvs thick, coriac., on broad flat petioles ± 5 mm. long. Lamina ± 10-20-(25) × 10-15-(20) mm.; obovate to broad-oblong to elliptic in outline, cuneately narrowed to base; coarsely, deeply dentate; teeth very narrow-triangular, blunt, elongating to ± 6 mm. Fls ± 10 mm. long, on stout peduncles up to 5 cm. long. Calyx 5-7 mm. long, persistent; lobes linear, thick, obtuse, elongating to c. 8 mm. in fr. Corolla white, hardly > calyx, split to near base into 2 lips; upper lip with 2 narrow segs, lower 3-lobed to c. ⅓ way; anthers not awned. Capsule coriac., ± 10-12 mm. long, broad-obovoid to suborbicular.

n = 7

Glabrous or glabrate herb; sap clear. Stems to c. 15 mm tall, simple or sparingly branched, slender, rooting at nodes, usually decumbent. Lvs subsessile, 3-8 mm diam., ± orbicular, rather coarsely sinuate-dentate in upper 1/2, dark green, often purplish below, rather thick. Peduncles filiform, 5-6-(10) cm long. Calyx c. 4 mm long, divided to nearly 1/2 way; lobes c. 2 mm long, very narrow-triangular, acuminate. Corolla 5-10 mm long, white, pale blue or pale pink, deeper coloured in bud; upper lobes linear-oblong, acute; lower lobes obovate or obovate-oblong, ± apiculate. Capsule 5-9 mm long, narrow-obovoid to turbinate.