Article

The Mediterranean region is one of the centres of diversity of the genus Allium. Representatives of 4 out of 6 subgenera occur here, reflecting the rather heterogeneous evolutionary history of Allium in the Mediterranean area. Some are representatives of the basic stock of the genus, belonging e.g. to A. subg. Rhizirideum (mainly distributed in continental temperate Eurasia, and with rather unspecialized features) and subg. Amerallium (with the subendemic A. sect. Molium and some other small, derived species groups, adapted by their growth rhythm to the Mediterranean climate with its prolonged dry season). The majority of species belong to A. subg. Allium, whose evolution and radiation can be correlated to the development of vast arid regions, open for colonization, after the shrinking of the Tethys sea in the so-called Old Mediterranean region. The few Mediterranean species of A. subg. Melanocrommyum represent eastem immigrations from the Irano-Turanian province.