What is Astragalus wiesneri? Disentangling a new species from its relatives in section Anthylloidei

Here, we describe and illustrate a new alpine species of Astragalus sect. Anthylloidei from Iran. Astragalus wiesneri sp. nov., an interesting and rare species, is only known from the type locality in the Bul Mountain (near Eghlid city) in the southern Zagros Mountains. The new species is compared with close relatives, including A. nigrohirsutus and A. lalesarensis, which are also endemic to Iran. In addition, we assembled a dataset of nrDNA ITS sequences of 21 species (22 accessions) representing A. sect. Anthylloidei and ten species of other related spiny-cushion forming sections. Maximum likelihood methods and Bayesian Inference retrieved A. wiesneri sister to A. nigrohirsutus, a species growing in the same area as the new species. The description of A. wiesneri is presented along with a distribution map, some ecological information, field images, conservation status, and pertinent notes.