Physical description. Closely related to raspberries (also in the genus Rubus), blackberry plants have biennial canes (stems) that are characteristically covered with prickles and are erect, semi-erect, or trailing; the thornless blackberry is a modern development.There are many ways to enjoy blackberries. Along with eating them alone, they can be used in jams, jellies, and mixed with other fruits. You can combine other ingredients like yoghurt and seeds to create a delicious and healthy summer dish.