Petiol anatomy of some taxa Anchusa undulata L. subsp. hybrida (Ten.) Coutinho, Anchusa azurea Miller var. azurea, Anchusa leptophylla Roemer & Schultes subsp. incana (Ledeb.) Chamb.) of Genus anchusa L. (Boraginaceae)

In this study, three taxa of the genus Anchusa L. (Boraginaceae) distributed in Turkey (A. leptophylla Roemer & Schultes subsp. incana (Ledeb.) Chamb., A. azurea Miller var. azurea, A. undulata L. subsp. hybrida (Ten.) Coutinho) petiole anatomical structures were investigated. Sections taken from the petiole of the samples belonging to the taxa were made into permanent preparations and examined under the light microscope (LM). Photographs of the anatomical sections of the species were taken with a light microscope with a camera. Cell diameter measurements were made in the program called LASEZ on these photographs. In order to better determine the variations, the highest (maximum) and the smallest (minimum) values of the anatomical petiole anatomical measurements were determined, and the petiole anatomical characteristics of the species were determined. As a result of the study, petiole shapes vary according to species. In A. leptophylla subsp. incana and A. azurea var. azurea, A. undulata ssp. hybrida it is straight and slightly concave. There is a cuticle layer on the single layered epidermis. The epidermis is single-rowed A. leptophylla ssp. incana with thick walls, and the cells are angular or oval. Chlorenchyma layer consisting of one or more rows of cells was found under the epidermis layer in the species. The collenchyma layer is multi-rowed at the petiole corners. The parenchyma layer covers a large area in all species. In the middle of the petiole, there is a single large vascular bundle, the shape of which varies according to the species (arc-shaped in A. leptophylla ssp. incana and A. undulata subsp. hybrida, slightly curved rectangular in A. azurea var. azurea). Towards the corners, there are different numbers of small vascular bundles of various sizes and generally rounded shapes. Conduction bundle is of closed collateral type. In addition, there are covering and glandular hairs on the epidermis of the species.