Culinary 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 flavor. In Europe, for many centuries the berries were used for culinary purposes much as citrus peel is used. The country in which they are used the most is
Iran, where they are referred to as
zereshk () in
Persian. The berries are common in
Persian cuisine in rice dishes, such as
zereshk polo (a dish of rice cooked in the Persian style with saffron and barberries, often served with chicken) and
morassa polo (literal translation "bejewelled rice", an opulent dish of rice with barberries and slivers of pistachio, almond, and orange peel) and as a flavouring for poultry. Because of their sour flavor, they are sometimes cooked with sugar before being added to Persian rice. Iranian markets sell dried zereshk. By virtue of their limited availability, specialised growing conditions, and the complexity of the harvesting process, they are considered expensive and so are served in the finest of Persian dishes. In Russia and Eastern Europe, it is sometimes used in jams as a source of
pectin (especially with mixed berries). An extract of barberries is a common flavoring for soft drinks, candies, and sweets.
Berberis aquifolium (Oregon grape) was traditionally eaten in small quantities by
Pacific Northwest tribes of North America.
Berberis microphylla and
B. darwinii (both known as
calafate and
michay) are two species found in
Patagonia in Argentina and Chile. Their edible purple fruit are used for jams and infusions.
Traditional medicine and adverse effects The dried fruit of
B. vulgaris is used in
herbal medicine. The chemical constituents include
isoquinoline alkaloids, especially
berberine. A full list of phytochemicals was compiled and published in 2014. The safety of using berberine for any condition is not adequately defined by
high-quality clinical research. Its potential for causing
adverse effects is high, including untoward interactions with
prescription drugs, reducing the intended effect of established therapies. The thorns of the barberry shrub have been used to clean ancient gold coins, as they are soft enough that they will not damage the surface but will remove corrosion and debris. The acidic young leaves are sometimes chewed for refreshment by parched hikers. ==In culture==