Germinating potato tuber, close-up. This is a chitting potato tuber of the variety blue St. Galler. At left is the vegetation cone, which is enveloped by new leaves. All parts of the plant, including the sprouts, contain anthocyanin in the cells, which cause an intense blue colour. The variety Blaue St. Galler is unique in a lot of traits. The purple colouration is caused by anthocyanin, which has an antioxidant effect. Magnification: x10 when printed 10 centimetres wide.