bloodroot, (Sanguinaria canadensis), plant of the poppy family (Papaveraceae), native throughout eastern and midwestern North America. It grows in deciduous woodlands, where it blooms in early spring, and is sometimes cultivated as an ornamental. The orange-red sap of the rhizomes was formerly used by Native Americans for dye. The rhizomes also contain the medical alkaloid sanguinarine. Although the plant is considered toxic, overcollection for use as an herbal medicine and unfounded cancer treatment has depleted wild populations throughout much of its native range.
Bloodroot has a shining white eight-petalled cup-shaped flower with bright yellow stamens (male reproductive structures) in the centre. The 4- to 6-cm (2-inch) flower is borne on a 20-cm reddish stalk. A large veiny half-opened leaf enfolds the flower stem. After the flower has bloomed, the leaf opens into a much-lobed blue-green round form. The seeds feature fleshy structures known as elaiosomes to attract ants for dispersal.