Fruit preserve Blueberry - with sweet, midnight blue blueberries from wild harvesting. The blueberry (Vaccinium myrtillus) is a plant of the family (Ericaceae) with about 100-150 species. The most common variety used by Alpe Pragas is the wild blueberry "Vaccinium myrtillus". The fruits contain a lot of carotene, vitamin B6, vitamin C and magnesium. Due to the anthocyanins they contain they colour the mouth and the teeth blue when consumed.