Dewberries are a close relative of blackberries, and unlike brambles the stems trail along the ground. The berries are blue-black with a blue-grey bloom, generally smaller but with larger segments than blackberries. It's commonly found near the coast, and often on sand dunes - the name probably originates from 'Dune berry'. They can be used for jams, jellies etc in the same way as blackberries, but obviously are more difficult to collect.