A pile of saffron threads (each about 20 mm in length) from Iran. Saffron is a spice derived from the flower of the saffron crocus and is among the world's costliest spices by weight. In Western countries, the average retail price is $2200/€1550/£1100 per kilogram ($1,000/€700/£500 per pound). Besides its use as a seasoning, it has also been used in its history as fragrance, dye, and medicine.Photo credit: Rainer Zenz