The wild precursor of domesticated saffron crocus was likely "Crocus cartwrightianus", which originated in Crete or Central Asia; "C. thomasii" and "C. pallasii" are other possible sources. Although some doubts remain on its origin, it is believed that saffron originated in Iran (Persia). However, Greece and Mesopotamia have also been suggested as the possible region of origin of this plant. The saffron crocus is now a triploid that is "self-incompatible" and male sterile; it undergoes aberrant meiosis and is hence incapable of independent sexual reproduction—all propagation is by vegetative multiplication via manual "divide-and-set" of a starter clone or by interspecific hybridisation. If "C. sativus" is a mutant form of "C. cartwrightianus", then it may have emerged via plant breeding, which would have selected for elongated stigmas, in late Bronze Age Crete.