WordNet sense 1 (erect European blueberry having solitary flowers and blue-black berries):

whortleberry, blaeberry, whinberry, Viccinium myrtillus

WordNet sense 2 (erect blueberry of western United States having solitary flowers and somewhat sour berries):

mountain blue berry, thin-leaved bilberry, Viccinium membranaceum

WordNet sense 3 (blue-black berries similar to American blueberries):

European blueberry