"At least two species of choke berries are cultivated widely, black and red. The plant bears numerous small, about 1 cm size fruits with relatively thick, pigmented skin. Red berries are sweeter in taste than black berries; the latter are slightly bitter in taste; however, black and blue berries are rather rich in anthocyanin anti-oxidants...."
http://www.nutrition-and-you.com/choke-berry.html
