Widespread lawn and roadside weed ( Capsella bursa-pastoris ) of the mustard family , native to the Mediterranean and now found worldwide.
Growing as high as 18 in. (45 cm), it is easily recognized by its flat, heart-shaped, green fruits, borne along the branching flower stalks, which arise from a dandelion-like rosette of deeply cut or almost entire leaves at the base and bear clusters of tiny white flowers. Shepherd's purse has been much studied to understand embryogenesis (development from zygote to seedling) in flowering plants.