Saffron is a plant. The dried stigmas (thread-like parts of the flower) are used to make saffron spice. It can take 75,000 saffron blossoms to produce a single pound of saffron spice. Saffron is largely cultivated and harvested by hand.
Due to the amount of labor involved in harvesting, saffron is considered one of the world's most expensive spices. The stigmas are also used to make medicine.
The Saffron plant is a member of the crocus family, which is cultivated for the sake of the stigmas of its flowers. Saffron is extremely expensive because it takes almost 13,000 stigmas hand-picked and dried from 4,300 flowers to make an ounce (28 g) of Saffron. People don't wander the hills and dales, though, looking for a flower here and a flower there: the Saffron crocuses are cultivated 6 inches (15 cm) apart in rows in huge fields.
Research has indicated that Crocin, Safranal and Picrocrocin from saffron may be involved in ant-cancer activity by inhibiting the growth of human cancer cells in vitro.
Store in an airtight container in a dark, cool, dry place. After 6 months, the threads will start to weaken in flavor.