In Iranian culture, barberries are incorporated into certain wedding dishes as a symbol; the sourness of the small, red berries, it is said, representing the occasional sourness of life. The South Khorasan province in Iran is the main area of zereshk (Barberry) 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.