Perennials 15-35 cm tall. Roots to 25 × 1.5 cm. Stems ascending, simple, glabrous. Basal leaves petiole 3.5-5 cm, membranous; leaf blade lanceolate to broadly lanceolate, 7-25 × 1.5-4 cm, base narrowed, margin scabrous, apex acuminate, veins 3-7. Stem leaves 3-5 pairs; petiole to 2 cm, membranous; leaf blade lanceolate, 3-6 × 0.5-2.2 cm, base obtuse, margin scabrous, apex acuminate, veins 1-3. Inflorescences crowded into terminal clusters, many flowered, rarely also in few-flowered axillary whorls. Flowers sessile. Calyx tube 4.5-7 mm, membranous, usually split on 1 side; lobes 5, triangular, 0.5-1 mm. Corolla pale yellow, tubular, (1.5-)1.8-2(-2.5) cm; lobes ovate, 3-3.5 mm, margin entire, apex obtuse; plicae triangular, 1-1.5 mm, oblique, margin entire, apex acute. Stamens inserted at basal part of corolla tube; filaments 5-8 mm; anthers narrowly ellipsoid, 2-2.5 mm. Style 2-2.5 mm; stigma lobes oblong. Capsules sessile, narrowly ellipsoid, 1.3-1.5 cm. Seeds light brown, ellipsoid, 1.4-1.6 mm. Fl. and fr. Aug-Sep.