Boysen is a hybrid between red raspberry and blackberry, but the exact parentage is not known. Generally thought of as a type of blackberry, given its fruit characteristics. Fruit are large, soft, dark purple and covered with a dusty bloom. Flavor is very good, unique. Trailing growth habit. High yields.
- Released by Walter Knott (developed by Rudolph Boysen in Napa, Calif.) in 1935
- Exact parentage unknown, but believed to be Logan (R. ideas crossed with R. ursinus) crossed with Eastern dewberry