Crocus sativus
Saffron is considered to be the most valuable spice by weight. Depending on the size of harvested stigmas, 50,000–75,000 "Crocus sativus" plants are needed to produce about 1 pound of saffron; each flower only produces three stigmas. Stigmas should be harvested mid-morning when the flowers are fully opened. The saffron crocus ("Crocus sativus") should not be confused with "meadow" saffron or autumn crocus ("Colchicum autumnale") which is poisonous.