Stems simple or sparingly branched, 4-angled, up to ± 25 cm. tall. Lvs rather sparse, in opp. pairs, sessile, 6·5-15 × 5-10 mm., ovate to broad-ovate or suborbicular, obtuse or subacute. Fls c. 6·5 mm. long, in terminal dichotomous cyme; calyx-lobes 5, narrowly ovate-lanceolate, acute, with rigid narrowly winged keel. Corolla-tube c. 4 mm. long, straight; lobes 5, pale yellow, c. 3 mm. long, twisted after anthesis. Anthers narrow-oblong, gland-tipped, on very short filaments. Style short, stigma ± 0.75 mm. long. Capsule ovoid-ellipsoid, c. 5 mm. long.