Öz Prospero seisumsianum (Ruk?ans & Zetterl.) Yıldırım, a species recently described in southeastern Turkey, was recorded for the first time in the flora of Iraq based on samples collected from the Amadya and Duhok areas (northern Iraq). Our contribution here will be to find out more about its description, cytology, and chorology. The specimen collected from the Mesopotamian dry plain differs slightly from those collected from the mountainous Zagros forest area, but converges after a cultivation period. Both are treated here as P. seisumsianum and have the same genome size (2C = 8.77 ± 0.24 pg) corresponding to a diploid level. Three chromosome counts gave the same 2n = 2x = 14 karyotype. We hypothesize here that all the historical mentions of P. ?autumnale? in Iraq actually correspond to P. seisumsianum. Comparative morphological description, genome size, ecological niche, and biogeography of the related taxa, and a revised key for Prospero taxa from the Irano-Anatolian enlarged to its Mediterranean border are given in the present study.