Boysenberry

A boysenberry is an aggregate fruit. It has large seeds and a maroon color. It is commonly used in jams and pies. When cooked into jams and pies, it changes color.
It is not a natural species: it is a cultivated variety. A 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").