Allium dumanii Koyuncu & Kocyigit, a new species in A. sect. Codonoprasum (Rchb.) Endl. from Kahramanmaras and Malatya, Anatolia, is described and illustrated. It is compared with the possibly related A. armenum Boiss. & Kotschy. The karyomorphology of A. dumanii and A. armenum is also presented and discussed. The chromosome number of the new species is 2n = 16.