Berberis vulgaris grows in the wild in much of Europe and West Asia. It produces large crops of edible berries, rich in vitamin C, but with a sharp acid flavour. In Europe for many centuries the berries were used for culinary purposes in ways comparable to how citrus peel might be used. Today in Europe they are very infrequently used. The country in which they are used the most, is Iran where they are referred to as "Zereshk" (زرشک) in Persian. The berries are common in Iranian (Persian) cuisine such as in rice pilafs (known as "Zereshk Polo") and as a flavouring for poultry meat. Due to their inherent sour flavor, they are sometimes cooked with sugar before being added to Persian rice. Iranian markets sell Zereshk dried. In Russia they are sometimes used in jams (especially the mixed berry ones) and extract from them is a common flavouring for soft drinks and candies/sweets.