The cultivated saffron (saffron crocus C. sativus) flowers in the autumn and comes up every year, so it is known as a perennial plant. It does not grow wild, and is now a triploid form of the eastern Mediterranean plant called Crocus cartwrightianus. It is thought that C. cartwrightianus came from Crete.he cultivated saffron (saffron crocus C. sativus) flowers in the autumn and comes up every year, so it is known as a perennial plant. It does not grow wild, and is now a triploid form of the eastern Mediterranean plant called Crocus cartwrightianus. It is thought that C. cartwrightianus came from Crete.