The very berry for your next jam session. Marionberry is a type of blackberry developed by the USDA-ARS breeding program in cooperation with Oregon State University. This prolific variety produces a hefty harvest of delicious, bright, glossy fruit. The tart, sweet flavor makes for delicious desserts, jams and jellies. Vitamin-rich fruit is only 80 calories per cup. Marionberry, 1 Plant, White, Burpee