Stems erect, ca. 1 m tall, simple, glabrous. Cauline leaves sessile; blade oblong or ovate-orbicular, 5-7 × 1.5-3 cm, papery, lucid, glabrous, base rounded or obtuse, margin crenate or irregularly serrate, apex acute or rounded. Flowers several in a compact pseudoraceme. Hypanthium glabrous; calyx lobes ovate-lanceolate, ca. 5.5 × 2 mm, nearly 2 × as broad at middle as at base, distinctly reticulate veined, margin entire, apex obtuse or acute. Corolla broadly campanulate, ca. 2 cm in diam. Disk ca. 4 × 1.5 mm, glabrous. Style slightly longer than corolla. Capsule obovoid, 7-8 × 4-6 mm. Fl. and fr. Aug. 2n = 102.

E Jilin [Japan, N Korea].