2n = 14

Glabrous herb with pale yellow, acrid sap. Root system extensive. Stems tough, ascending through rock debris and rooting at nodes, to c. 10 cm tall above surface. Lvs with broad flat petioles c. 5 mm long. Lamina 10-20-(25) × 10-15-(20) mm, obovate to broad-oblong or elliptic, thick and coriaceous, prominently dentate with narrow triangular teeth, obtuse. Peduncles stout, to 5 cm long. Calyx lobes 5-8 mm long, linear, obtuse. Corolla c. 10 mm long, white, divided nearly to base; upper lip with 2 narrow segments; lower lip lobed to c. 1/2 way; lobes oblong or elliptic-oblong, obtuse. Capsule 10-12 mm long, broad-ovoid to suborbicular.