Wahlenbergia rhytidosperma Thulin

Probably perennial herb with a taproot and numerous, decumbent, filiform stems up to 15 cm long, glabrous or pubescent. Leaves opposite, except for the inflorescence region where alternate leaves often occur, thin, very narrowly to broadly elliptic, up to 9 mm long and 2-3.2 mm wide, acute at the apex, narrowing at the base into a short petiole, glabrous or pubescent; margin not incrassate, with 1-3 denticles on each side or sometimes entire; mid vein somewhat protruding beneath. Inflorescence frondose, one-to few-flowered, with the flowers terminal or in dichotomous forks; pedicels filiform, up to 16 mm long, glabrous or sparsely pubescent. Hypanthium hemispherical or broadly obconical, c. 10-nerved, glabrous or pubescent. Calyx-lobes 0.8-2.4 mm long, narrowly triangular, with hyaline often recurved tips, entire, glabrous or pubescent. Corolla 3.5-6 mm long, lobed to about half the length, white or mauve, glabrous, or pubescent on the outside of the lobes; tube 1.8-3 mm long. Stamens with the filament-bases narrowly dilated or almost linear, sparsely-ciliate; anthers 0.7-1 mm long. Ovary semi-inferior, 3-locular. Style about equalling the corolla-tube, eglandular, slightly thickened in the upper part, glabrous below; lobes 3, ±0.5 mm long. Capsule 3-locular, 1.5-2 mm long, c. 10-nerved with 3 valves, 0.5-0.8 mm long. Seeds elliptic to broadly elliptic in outline, 0.5-0.6 mm long; testa rugulose.