Description from Flora of China
Paederota axillaris Siebold & Zuccarini, Abh. Math.-Phys. Cl. Königl. Bayer. Akad. Wiss. 4(3): 144. 1846; Botryopleuron formosanum Masamune; Calorhabdos simadai Masamune.
Rhizomes short, horizontal. Stems arching and rooting apically, basally terete, angular in middle and apically, glabrous, rarely sparsely hairy on angles. Leaves alternate; petiole short; leaf blade ovate to ovate-lanceolate, 5-12 cm, papery, glabrous, margin obliquely deltoid dentate, apex acuminate. Inflorescences axillary, rarely terminal, 1-3 cm. Bracts and calyx lobes linear-lanceolate to subulate, glabrous or ciliate. Corolla purple to purple-red, 4-5 mm, straight; limb actinomorphic; lobes ca. 2 mm, narrowly triangular. Stamens slightly to conspicuously exserted, exceeding corolla by ca. 2 mm; filaments hairy; anthers 0.6-1.5 mm. Capsule ovoid-globose, ca. 3 mm. Seeds oblong, ca. 0.6 mm; seed coat obscurely reticulate. Fl. Jul-Sep.
Forests, grasslands at forest margins, shaded places in valleys; low elevations. Anhui (Shucheng Xian), Fujian, Guangdong (Ruyuan Yao Zizhi Xian), S Jiangsu, Jiangxi, Taiwan (Xinzhu Xian), Zhejiang [Japan].