<P> Saffron (pronounced / ˈsæfrən / or / ˈsæfrɒn /) is a spice derived from the flower of Crocus sativus, commonly known as the "saffron crocus". The vivid crimson stigmas and styles, called threads, are collected and dried to be used mainly as a seasoning and colouring agent in food . Saffron, long among the world's most costly spices by weight, was probably first cultivated in or near Greece . C. sativus is probably a form of C. cartwrightianus, that emerged by human cultivators selectively breeding plants for unusually long stigmas in late Bronze Age Crete . It slowly propagated throughout much of Eurasia and was later brought to parts of North Africa, North America, and Oceania . </P> <P> Saffron's taste and iodoform or hay - like fragrance result from the chemicals picrocrocin and safranal . It also contains a carotenoid pigment, crocin, which imparts a rich golden - yellow hue to dishes and textiles . Its recorded history is attested in a 7th - century BC Assyrian botanical treatise compiled under Ashurbanipal, and it has been traded and used for over four millennia . Iran now accounts for approximately 90% of the world production of saffron . </P>

What part of saffron is used to make the spice