The main difference between Blackberry and Boysenberry is that the Blackberry is a fruit of Rubus subg. Rubus and Boysenberry is a cross between a European Raspberry (Rubus idaeus), a Common Blackberry (Rubus fruticosus), an American Dewberry (Rubus aboriginum) and a Loganberry (Rubus × loganobaccus).
The blackberry is an edible fruit produced by many species in the genus Rubus in the family Rosaceae, hybrids among these species within the subgenus Rubus, and hybrids between the subgenera Rubus and Idaeobatus. The taxonomy of the blackberries has historically been confused because of hybridization and apomixis, so that species have often been grouped together and called species aggregates. For example, the entire subgenus Rubus has been called the Rubus fruticosus aggregate, although the species R. fruticosus is considered a synonym of R. plicatus.
The boysenberry is a cross among the European raspberry (Rubus idaeus), European blackberry (Rubus fruticosus), American dewberry (Rubus aboriginum), and loganberry (Rubus × loganobaccus).It is a large 8.0-gram (0.28 oz) aggregate fruit, with large seeds and a deep maroon color.
A fruit-bearing shrub of the species Rubus fruticosus and some hybrids.
The soft fruit borne by this shrub, formed of a black (when ripe) cluster of drupelets.
A hybrid berry created from crossing blackberry, red raspberry, and loganberry.