Investigation of morphological, anatomical and palynological characters of Scabiosa columbaria taxa in Turkey

The purpose of this study was to determine the morphological, anatomical and palynological features as well as their taxonomical importance of the S. columbaria taxa, in the genus Scabiosa L. which is naturally distributed in Turkey. S. columbaria taxa were consisted of 3 subspecies and 4 varieties. The plant material of this study was collected during field work in 2018 and 2019 and stored in 70 % alcohol. Roots, leaves and stem segments of each plant material were embedded in paraffin, laterally cut with a microtome, dyed and finally prepared as permanent slides. The Woodhouse method was used to investigate pollen features of the investigated plants under light and electron microscope. Stoma characteristics of taxa were determined based on transparent leaf samples (after using a clearing method). Examinations of root sections of the S. columbaria taxa showed that the peridermis layer as the outermost part was followed by 8-20 rows of cortex layer, 15-40 rows of phloem layer and tracheal elements at the central part. The endodermis layer was not clearly distinguished in the root sections. Further, druse crystals were found in the root sections of S. columbaria subsp. columbaria var. columbaria and S. columbaria subsp. columbaria var. intermedia. At the outermost part of the stem sections, a double-row epidermis layer was observed with the inner region being filled with 2-5-rows of cortex layers, vascular bundles and parenchymatic cells. The examination of leaf sections showed that, a single row epidermis layer was present on the lower and upper surface, vascular bundles were lined at regular intervals in the middle part and that a mesophyll layer of parenchymatic cells was present. Based on leaves section, it was determined that the leaf structure was monofacial. Druse crystals were found in the mesophyll layer of leaves of S. columbaria subsp. columbaria var. columbaria, S. columbaria subsp. ochroleuca var. webbiana and S. columbaria subsp. paphlagonica. The stoma type of S. columbaria taxa was found to be anisocytic. S. columbaria subsp. paphlagonica had the largest stomata among the investigated taxa. Pollens of the studied taxa were radial symmetrical, isoporal and tricolpate. The pollen shape of the species S. columbaria subsp. columbaria var. columbaria prolate, S. columbaria subsp. columbaria var. intermedia subprolate, S. columbaria subsp. ochroleuca var. ochroleuca subprolate, S. columbaria subsp. ochroleuca var. webbiana prolate and S. columbaria subsp. paphlagonica was found to be prolate. The pollen surface ornamentation was found to be echinate in all taxa. The data obtained in this work on S. columbaria taxa was similar to the existing Turkey Flora data. Some characters which are not available in the Turkey Flora such as peduncle length, corona, bottom, stem and upper leaf length were given as metric measurements in this study. As a result of anatomical and palynological studies, taxa have been found to have similar anatomy and pollen structures. We therefore conclude, that these species cannot be distinguished based on anatomy and pollen characteristics.