Usually prickly, fruit-bearing bush of the genus Rubus, in the rose family, native chiefly to northern temperate regions. The blackberry is abundant in eastern North America and on the Pacific coast; in Europe it is common in thickets and hedges. Its usually biennial, prickly, and erect, semierect, or trailing stems bear leaves with usually three or five oval, coarsely toothed, stalked leaflets; white, pink, or red flowers in terminal clusters; and black or red-purple aggregate fruits. The several trailing species are commonly called dewberries. Blackberries are a fairly good source of iron and vitamin C.