Description from Flora of China
Ruellia antipoda Linnaeus, Sp. Pl. 2: 635. 1753; Bonnaya antipoda (Linnaeus) Druce; B. veronicifolia (Retzius) Sprengel; Gratiola veronicifolia Retzius; Ilysanthes antipoda (Linnaeus) Merrill; Lindernia veronicifolia (Retzius) F. Mueller; Vandellia veronicifolia (Retzius) Haines.
Annuals to 30 cm tall. Roots fibrous, fascicled. Stems suberect or prostrate basally and rooting from lower nodes then ascending, many branched, channeled, glabrous. Petiole short and wide; leaf blade oblong, oblong-lanceolate, oblong-oblanceolate, or linear-lanceolate, 0.8-4 X 0.6-2 cm, glabrous, base cuneate and decurrent, margin obscurely to sharply serrate or subentire, apex acute to rounded. Racemes terminal, to 15 cm, 2-20-flowered; bracts subulate. Pedicel to 1.5 cm, ascending, spreading, to deflexed in fruit. Calyx lobed to base; lobes lanceolate, hispidulous along midrib and edges. Corolla purple, purplish white, or white, to 1 cm; tube to 7 mm; lower lip 3-lobed, lobes subequal; upper lip 2-lobed. Fertile stamens 2, posterior; filaments unapendaged. Reduced stamens 2, anterior; filaments slightly curved, glandular. Stigma lamellate. Capsule cylindric, 2 X or more as long as persistent calyx. Seeds brown, irregularly triangular-ovoid; seed coat reticulate. Fl. and fr. spring-autumn.
According to T. Yamazaki (Fl. Thailand 5(2): 198. 1990) Lindernia viaticaLinderniaviatica (Kerr ex Barnett) Philcox occurs in Taiwan. It closely resembles L. antipoda, but we have not
seen any specimens from Taiwan.
Rice fields, wet grassland; below 1700 m. Anhui, Fujian, Guangdong, Guangxi, Hubei, Hunan, Jiangsu, Jiangxi, Sichuan, Taiwan, Yunnan, Zhejiang [Bhutan, Cambodia, India, Japan (Ryukyu Islands), Laos, Malaysia, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, Vietnam; Australia, Pacific Islands].