Shedding light on the geographical distribution, population size and inflorescence coloration variety of Royal Irises (Iris section Oncocyclus) family in West Bank, Palestine

Abstract

Palestine has rich floristic diversity due to its location, diverse biogeographical zones, and various topographical features. The Royal Irises (Iris section Oncocyclus), are a monophyletic group of herbaceous geophytes, consisting of 33 species, endemic to the Middle East. Within the West Bank of Palestine, three Royal Irises are documented. However, their distribution, population size, and status are not studied comprehensively. This study focused on evaluating the occurrence, distribution range, population size, status, number of flowers, inflorescence coloration variety, and habitats of the vulnerable and endemic Iris haynei, the endangered and sub-endemic Iris lortetii, and the vulnerable and sub-endemic Iris atrofusca. I. lortetii was found in 10 sites within Nablus district, with more than 12625 clones and 25088 flowers flowers recorded. I. haynei were documented in 4 sites within Jenin district, three are new to science, where 10729 clones and 9562 flowers were recorded. I. atrofusca was reported in 13 localities in Tubas and Ramallah districts, where 1853 clones and 8460 flowers were recorded, whereas six locatities are new to science. 12, 12, and 7 unique variations in coloration of inflorescences were observed for I. lortetii, I. atrofusca, and I. haynei, respectively. The results indicate that the population size and the distribution range of the three Royal Irises are larger than previously reported, whereas the documented inflorescences’ coloration variations are unique and considerable. This study sheds light on hotspot occurrence sites of endangered and vulnerable species in Palestine, which can assist in laying adequate conservation actions and management plans in the future.