It"s harvest time for saffron, the precious seasoning that"s mostly grown in Iran, but used in cuisines around the world. Saffron is derived from the saffron crocus, an autumn-flowering plant with purple petals as richly hued as the vivid crimson stigmas (called "threads") in the center of the bloom. These threads are carefully extracted by hand with tweezers and dried before they"re used for cooking. Each flower comes with just three threads, and it takes a lot of them—roughly 75,000 crocuses will yield just one pound of saffron. The entire harvest can last only about a week or two, because that"s the short life of the saffron crocus bloom.