紫苏草 zi su cao

Ambulia aromatica Lamarck, Encycl. 1: 128. 1783; Limnophila aromaticoides Yang & Yen; L. chinensis subsp. aromatica (Lamarck) T. Yamazaki; L. gratissima Blume; L. punctata Blume; L. punctata var. subracemosa Bentham.

Annuals or perennials. Stems 30-70 cm, simple to much branched, glabrous or glandular, base decumbent and rooting from nodes. Leaves opposite or in whorls of 3, sessile, ovate-lanceolate to lanceolate-elliptic, 1-5 X 0.3-1.5 cm, base semiamplexicaul, margin crenate and serrate; veins pinnate. Flowers solitary in leaf axils or in terminal or axillary racemes. Pedicel 0.5-2 cm, glabrous or glandular. Bracteoles linear to linear-lanceolate, 1.5-2 mm. Calyx 4-6 mm, glabrous or glandular pubescent, with raised veins in fruit. Corolla white, blue-purple, or pink, 1-1.3 cm, sparsely and finely glandular, inside white villous. Style apex dilated; stigma short, 2-lamellate. Capsule ovoid, ca. 6 mm. Fl. and fr. Mar-Sep.

Around reservoirs and other moist places; low elevations. Fujian, Guangdong, Guangxi, Hainan, Jiangxi, Taiwan [Bhutan, India (Darjeeling), Indonesia (Java), Japan, Korea, Laos, Philippines, Vietnam; Australia].

The characters used by Yang & Yen (Bot. Bull. Acad. Sinica 38: 285-295. 1997) to distinguish Limnophila aromaticoides from L. aromatica clearly fall within the variation range of the latter.