Plants glabrous throughout. Stems erect, multi-branched, 60-90 cm. Leaves alternate; petiole 0.5-2 cm; blade ovate to ovate-lanceolate, 5-14 × 3-7 cm, base rounded, decurrent, margin crenulate, apex acute to shortly acuminate. Flowers solitary, terminal; pedicels 3-10 cm. Calyx entirely free from ovary; lobes oblong-lanceolate, 18-30 × 6-10 mm, margin entire, apex acute. Corolla pale creamy yellow, with pale purple veins, campanulate; tube 1.6-2 × 2.4-3 cm; lobes triangular, 1.2-1.5 × 0.8-1.2 cm, apex acute. Filaments filiform, ca. 8 mm.