Hedyotis (Hedyotis Diffusa) is an annual herb, widely distributed in the orient and tropical Asia, such as China, Japan and Indonesia. Generally, the plant grows in humid fields and ridges of farmlands, ascending to procumbent, to 50 cm tall; the stem is slightly flattened to terete, glabrescent to glabrous and the papilla was observed in the transverse section of the stem; the leaves are opposite, sessile or subsessile and blade drying membranous, linear, narrowly elliptic, 1–4 × 0.1–0.4 cm; the flowers with pedicels are pairs in axillary racemes and the corolla is white.