Cowpea Witchweed

Striga gesnerioides, the cowpea witchweed, also called the indigo, purple, or tobacco witchweed, is a species of flowering plant in the family Orobanchaceae. It is native to Africa, the Arabian Peninsula, and the Indian Subcontinent, and it has been introduced to Florida. An erect subshrub, it is found in the seasonally dry tropics. As its common name suggests, it is a serious root hemiparasite of cowpea (Vigna unguiculata), and related species, especially affecting subsistence farmers.