Description from Flora of China
Lobelia caespitosa Blume; L. campanuloides Thunberg; L. chinensis var. albiflora (F. E. Wimmer) F. E. Wimmer; L. radicans Thunberg; L. radicans var. albiflora F. E. Wimmer; Pratia thunbergii G. Don.
Herbs, perennial. Stems decumbent, slender, 6-30 cm tall, glabrous, lower nodes rooted. Leaves alternate, sessile or petiole to 1 mm; blade narrowly elliptic, elliptic, or lanceolate, 7-26 × 1.5-7 mm, glabrous, base rounded, obtuse, or broadly cuneate, margin entire or obviously serrate at upper part, apex acute or acuminate. Flowers usually solitary, axillary at upper leaves of branches; pedicels slender, 1.2-2.5(-3.5) cm; bracteoles 2 at base, ca. 1 mm, glabrous, or absent. Hypanthium narrowly obconical, base attenuate, not well distinguished from pedicel, 3-5 mm, glabrous; calyx lobes lanceolate, ± as long as tube, margin entire or with a pair of denticles. Corolla rose, white, or bluish, 10-15 mm, divided to base at back, white villous below throat; lobes all spreading in a plane on anterior side; lateral 2 lobes lanceolate or oblanceolate, longer than others, central 3 elliptic. Filament tube 6-8 mm, connate above middle, glabrous; anther tube 2-2.5 mm, back glabrous or sparsely villous. Capsule obconic, 6-7 mm. Seeds broadly elliptic, compressed, pitted. Fl. and fr. May-Oct.
By paddy fields, streams, among wet grasses. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Sichuan, Taiwan, Yunnan, Zhejiang [Bangladesh, Cambodia, India, Japan (including Ryukyu Islands), Korea, Laos, Malaysia, Nepal, Sri Lanka, Thailand, Vietnam].