Saffron is a key seasoning, fragrance, dye, and medicine in use for over three millennia. One of the world's most expensive spices by weight, saffron consists of stigmas plucked from the vegetatively propagated and sterile Crocus sativus, known popularly as the saffron crocus. The resulting dried "threads" are distinguished by their bitter taste, hay-like fragrance, and slight metallic notes. The saffron crocus is unknown in the wild; its most likely precursor, Crocus cartwrightianus, originated in Crete or Central Asia; The saffron crocus is native to Southwest Asia and was first cultivated in what is now Greece.
From antiquity to modern times the history of saffron is full of applications in food, drink, and traditional herbal medicine: from Africa and Asia to Europe and the Americas the brilliant red threads were—and are—prized in baking, curries, and liquor. It coloured textiles and other items and often helped confer the social standing of political elites and religious adepts. Ancient peoples believed saffron could be used to treat stomach upsets, bubonic plague, and smallpox.
"Saffron, for example, was once less regarded than it is today because the crocus from which it is extracted was not particularly mysterious. It flourished in European locations extending from Asia Minor, where it originated, to Saffron Walden in England, where it was naturalised. Only subsequently, when its labour-intensive cultivation became largely centred in Kashmir, did it seem sufficiently exotic to qualify as one of the most precious of spices."
Saffron crocus cultivation has long centered on a broad belt of Eurasia bounded by the Mediterranean Sea in the southwest to India and China in the northeast. The major producers of antiquity—Iran, Spain, India, and Greece—continue to dominate the world trade.
The cultivation of saffron in the Americas was begun by members of the Schwenkfelder Church in Pennsylvania. In recent decades cultivation has spread to New Zealand, Tasmania, and California. Iran has accounted for around 90–93 percent of recent annual world production and thereby dominates the export market on a by-quantity basis.
Almost all saffron grows in a belt bounded by the Mediterranean in the west and mountainous Kashmir in the east. All other continents except Antarctica produce smaller amounts. In 1991, Some 300 t (300,000 kg) of whole threads and powder are gleaned yearly, of which 50 t (50,000 kg) is top-grade "coupe" saffron. Iran is by far the world's most important producer: in 2005 it grossed some 230 tonnes (230,000 kg) of dry threads, or 93.7 percent of the year's global total mass; much of the Iranian crop was bound for export. In the same year, second-ranked Greece produced 5.7 t (5,700.0 kg). Morocco and the disputed region of Kashmir, tied as the next-highest producers, each produced 2.3 t (2,300.0 kg). In decreasing order, Iran, Greece, Morocco, the Kashmir region in India, Azerbaijan, Spain, and Italy dominate the world harvest.