Immature burs of greater burdock, Arctium lappa. Other names include lappa, or beggar's buttons. It is a biennial plant of the Arctium (burdock) genus in the Asteraceae family, cultivated in gardens for its root used as a vegetable. The prickly heads of these plants (burrs) easily catch onto fur and clothing and were the inspiration for Velcro. For the plant this provides an excellent mechanism for seed dispersal.