Description from Flora of China
Paederota minima Retzius, Observ. Bot. 5: 10. 1789; Microcarpaea muscosa R. Brown.
Annuals. Stems slender, many branched, glabrous. Leaves sessile, amplexicaul, broadly linear to narrowly oblong, 3-4 X 1-2 mm, margin entire and somewhat thick; veins inconspicuous. Flowers sometimes 1 per node, alternate, sessile. Calyx ca. 2.5 mm; lobes narrowly deltoid-ovate, sparsely ciliate. Corolla pink, ovoid, as long as calyx. Capsule ovoid, shorter than calyx. Seeds brownish yellow, ca. 0.3 mm. Fl. Jul-Oct.
Paddy fields, swamps; 500-1400 cm. Guangdong, Guizhou (Jiangkou Xian), Taiwan, Yunnan (Jinghong, Xichou), Zhejiang (Huangyan Xian) [India, Indonesia, Japan, Korea, Malaysia, Thailand, Vietnam; Oceania].