Abstract

This study reports on the evaluation of the taxonomical, macro- and micro morphological, anatomical, palynological and cytological features, together with the geographical distribution of Arabis kaynakiae Daşkın (Brassicaceae), a Critically Endangered (CR) species from Turkey. The description of the species was updated following detailed studies on new specimens found in Karaman/Ermenek. The surface microphotographs of seeds and pollen were obtained using Scanning Electron Microscopy. The seed surface ornamentation is papillate and its margins minutely tuberculate. Pollen grains appear tricolpate, isopolar, subprolate in shape, with polar axis of 19.62 ± 0.33 µm and equatorial axis of 12.94 ± 0.17 µm. The exine thickness ranges from 1.68 to 1.87 µm; however, the intine thickness ranges from 0.21 to 0.39 µm. Arabis kaynakiae has pollen of coarse reticulate type surface ornamentation with slightly undulated muri. Anatomical characters of root, stem and leaf of the species were also given. The cytological investigations revealed that A. kaynakiae is diploid with 2n = 2x = 16 chromosomes. The discovered population of A. kaynakiae increased the known distribution range of the species in Turkey, and an updated evaluation of the species considering the IUCN criteria was provided.