burdock, common name of any plant of the genus Arctium of the family Asteraceae (aster family), coarse biennials indigenous to temperate Eurasia and mostly weedy in North America. The flowers, usually purple, are followed by roundish many-seeded burs. The great burdock (A. lappa) has been used medicinally and (in Japan) cultivated as a vegetable called gobo. The young leaves are eaten as a salad in Scandinavia and Japan. The common burdock is A. minus. The cocklebur is sometimes confused with burdock. Burdock is classified in the division Magnoliophyta, class Magnoliopsida, order Asterales, family Asteraceae.