木薯（学名：Manihot esculenta，英语：Cassava），又称树薯，是一种大戟科植物，原产于南美洲。

木薯为灌木，有肉质长圆柱形块根；茎直立有乳汁，叶子互生，掌状3－9深裂，裂片披针形至长椭圆状披针形；顶生或腋生疏散圆锥花序，单性花，雌雄花同在一花序上，雌花在上，雄花在下，没有花瓣；球形蒴果，有纵棱6条。

• 植株

• 花序

• 花

• 根部

• 横剖面

• Manihot esculenta - Museum specimen

Manihot esculenta (commonly called cassava (/kəˈsɑːvə/), Brazilian arrowroot, manioc, tapioca, and yuca) is a woody shrub native to South America of the spurge family, Euphorbiaceae. It is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates. Though it is often called yuca in Spanish and in the United States, it differs from the yucca, an unrelated fruit-bearing shrub in the family Asparagaceae. Cassava, when dried to a powdery (or pearly) extract, is called tapioca; its fermented, flaky version is named garri.