Campanula tetraphylla Thunberg in Murray, Syst. Veg., ed. 14, 211. 1784; Adenophora obtusifolia Merrill; A. polymorpha Ledebour var. rhombifolia H. Léveillé; A. polymorpha var. verticillata Franchet & Savatier; A. radiatifolia Nakai, nom. illeg. superfl.; A. radiatifolia var. abbreviata (H. Léveillé) Nakai; A. radiatifolia var. rhombifolia (H. Léveillé) Nakai; A. tetraphylla var. integrifolia Y. Z. Zhao; A. triphylla (Thunberg) A. Candolle; A. triphylla f. linearis (Hayata) Kitamura; A. triphylla var. tetraphylla (Thunberg) Makino; A. verticillata Fischer; A. verticillata var. abbreviata H. Léveillé; A. verticillata f. linearis (Hayata) Matsumura; A. verticillata var. linearis Hayata; A. verticillata f. triphylla (Thunberg) Makino; A. verticillata var. triphylla (Thunberg) Regel; Campanula triphylla Thunberg; C. verticillata Pallas (1773), not Hill (1765).

Root carrotlike, 7-16 × 1.5-1.8 cm. Stems up to 1.5 m tall, simple, glabrous, less often white hispidulous. Cauline leaves 3-6-verticillate, sessile or subsessile; blade broadly to narrowly elliptic, linear-lanceolate, or linear, 1.8-10 × 0.2-3.2 cm, both surfaces sparsely puberulent or glabrous, base cuneate or attenuate, margin serrate or serrulate, apex acuminate, acute, or obtuse. Inflorescence a narrow panicle with branches (cymes) mostly verticillate. Hypanthium obconic or campanulate, glabrous; calyx lobes subulate, linear, or linear-triangular, 1.5-4 mm, margin entire. Corolla blue to purple, tubular or narrowly funnelform, sometimes slightly constricted at throat, 7-10 mm; tube 2.5-7 mm in diam.; lobes deltoid, 1-2 mm. Disk narrowly tubular, 2-4 mm. Style 14-20 mm, strongly exserted. Capsule obovoid or broadly obovoid, 5-8 × 3-6 mm. Seeds yellow-brown, oblong, slightly compressed, 1-1.5 mm. Fl. (Feb-)Mar-Nov, fr. May-Nov. 2n = 34, 34+2B*.

Grassy places, scrub; low elevations but up to 2000 m in south. Anhui, Fujian, N Guangdong, Guangxi, Guizhou, Hebei, Heilongjiang, Henan (Lushi, Xinyang), Hunan (Xinning, Yizhang), Jiangsu, Jiangxi, Jilin, Liaoning, E Nei Mongol, Shandong (Muping), Shanxi (Lingkong Shan), Sichuan (Ebian, Emei Shan), Taiwan, Yunnan (Yanshan), Zhejiang [Japan (including Ryukyu Islands), Korea, Laos, Russia (Far East, E Siberia), N Vietnam].