Striga asiatica (L.) O. Kuntze is an annual semi-parasitic herb of Scrophulariaceae, with a plant height of 30 cm, erect stems and narrow leaves. The rest are strip-shaped and sometimes scaly. Flowers axillary or forming spikes at the top of stems; Calyx angular, lobes subulate; Corolla is usually yellow, red or white, and capsule is ovoid and surrounded by persistent calyx. Flowers bloom in autumn.

Witchweed is distributed in China's Yunnan, Guizhou, Guangxi, Guangdong, Hunan, Jiangxi, Fujian and Taiwan Province provinces. Tropical Asia and tropical Africa are widely distributed. It grows in low-altitude crops, barren hills and grasslands, fields, valleys and cultivated land. Parasitic on the root of the host.