Torenia cordifolia Roxb.

Annuals, 15-20 cm tall, sparsely white villous. Stems erect, branched from base; branches decussate, ascending, base sparsely diffuse. Petiole 0.8-1.5 cm; leaf blade ovate to cordate, 2.5-3.5 X 1.5-2.5 cm, sparsely villous, base cuneate and decurrent, margin coarsely triangular-serrate. Inflorescences 3-5-flowered axillary fascicles; bracts linear, ca. 5 mm. Pedicel 1.5-2 cm, often ascending. Calyx ovate-oblong, ca. 1.3 X 0.7 cm, base truncate to somewhat rounded, never decurrent, 5-winged; wings subundulate, ca. 2 mm wide, sometimes upper wing ca. 1 mm wide; lips triangular, 5 lobes becoming evident in fruit. Corolla blue-purple, 1.3-2 cm; lower lip lobes subequal; upper lip wider than long, margin somewhat involute, apex entire or emarginate. Anterior stamens appendages toothlike to filiform. Capsule oblong, ca. 9 X 4 mm. Fl. and fr. Sep-Nov.

Himalaya (Punjab to Bhutan), India, Burma, east to W. China.

Guizhou, Hubei (Xianfeng Xian), Sichuan, Yunnan [Bhutan, Cambodia, India (Darjeeling), Sikkim, Vietnam].

1000-1600 m

Mountain slopes, trailsides, wet places near streams; 600-1700 m.

西南蝴蝶草（学名：Torenia cordifolia）为玄参科蝴蝶草属下的一个种。