The stigma from the Crocus sativus flower. Saffron itself is a red filament with a floral, sweet flavor.
Persia (modern-day Iran), but possibly also Mesopotamia or Greece.
Persians likely introduced saffron to Kashmir by the 3rd century CE.
Saffron is the world’s most expensive spice by weight, as it is very difficult to harvest. It takes between 50,000 and 70,000 flowers to yield one pound of saffron.
New Oxford Book of Food Plants by John Vaughan et al. (2009)
The Oxford Companion to Food. 3rd ed., by Alan Davidson and edited by Tom Jaine (2014)
“Saffron” from Spice Jungle https://www.spicejungle.com/cooking-ingredients/spices/saffron