Zeresh is the Persian name for the dried fruit of Berberis vulgaris, which are widely cultivated in Iran. Iran is the largest producer of zereshk and saffron in the world. Zereshk and saffron are produced on the same land and the harvest is at the same time.
The South Khorasan province in Iran is the main area of zereshk and saffron production in the world. Barberry cultivation in Iran is concentrated in the South Khorasan province, especially around Birjand and Qaen. About 85% of production is in Qaen and about 15% in Birjand. According to evidence the cultivation of seedless barberry in South Khorasan goes back to two hundred years ago.
A garden of zereshk is called zereshk-estan.
Zereshk is widely used in cooking, imparting a tart flavor to chicken dishes. It is usually cooked with rice, called zereshk polo Recipe, and provides a nice meal with chicken. Zereshk jam, zereshk juice, and zereshk fruit rolls are also produced in Iran.
In colloquial Persian, zereshk is used as a term for showing dissent or disagreement, similar to the usage of "blowing a raspberry" in English. Although not a vulgar term in that context, it is not used in polite speech.