Découverte d’Allium cyrilli Ten. et actualisation de la section Melanocrommyum Webb & Berthel. (Amaryllidaceae) en Algérie et au Maghreb

The section Melanocrommyum Webb & Berthel. of the genus Allium L., with an Iranian-Anatolian center of diversity, has long been reduced to one species – the archeophytic segetal Allium nigrum L. – in western Europe and in the Maghreb. The discovery of Allium cyrilli Ten. in Algeria confirms the co-occurrence of two species in Maghreb, as well as in France and Spain according to recent studies. We provide a detailed and illustrated comparison of the two species from harvests and photos taken in situ in Algeria. A revision of the historical collections belonging to P and MPU herbaria allows to reject the hypothesis of an old underrecorded occurrence of A. cyrilli. Therefore, the species appears to have been relatively newly introduced in Algerian mountain crops. In the same time, A. nigrum seems to have declined in the lowland crops. An identification key based on the model of the Algerian flora of Quézel & Santa is provided.