The Saffron Crocus (Crocus sativus), one of around 80 species in the genus Crocus, is the source of saffron, a flavoring and coloring agent that has been derived from dried stigmas (the female flower parts) of the flowers since ancient times. The color of saffron is mainly due to the pigment crocin. Saffron is the most expensive spice in the world by weight and may also provide health benefits in some applications. Because it is so expensive, saffron is sometimes adulterated with other substances such as Colchicum autumnale).
(Vaughan and Geissler 1997; Kumar et al. 2009; Perez-Vidal et al. 2011 and references therein)