Boysenberry is one fruit you have probably never heard of. It used to be popular. The boysenberry was created by Rudolph Boysen in the 1920s. It is considered to be a variant of the blackberry, although it is actually a hybrid of a blackberry and either the loganberry or the red raspberry. For all we know, it could even be a hybrid of all three. However, it looks more like a blackberry than the other two.
There are claims that the boysenberry is actually a cross between the Eastern dewberry and the man-made loganberry. The loganberry was created in 1881 when James Logan crossed a raspberry with a wild blackberry. However, the boysenberry was not a commercial success due to its short shelf life. It decays just two days after harvest.
Stores tried prolonging the shelf life of the boysenberry by harvesting and shipping them before they ripened. The plan ultimately failed because unripe boysenberries taste acidic. These days, the boysenberry is only sold at farmers markets.