MICROMORPHOLOGICAL AND ANATOMICAL STUDIES OF CERTAIN SPECIES OF VERBASCUM (SCROPHULARIACEAE) IN WEST AZERBAIJAN, IRAN

The high morphological diversity among the species of the genus Verbascum causes problems in the delimitation of the species. Therefore, there is a difficulty in offering a natural and well organized classification for the species of the genus. This research was based on the leaf, seed coat and fruit anatomy, and seed micromorphology of the species growing in Iran. The shape and density rate of epicarpic idioblasts can be a determining character for Verbascum species. Two types of mesophyll were found within the species: Dorsiventral and Isobilateral. Also two types of thickness ratio of endocarp to pericarp (2/3, 1/2) were distinguished. However, a slight difference has been observed in the shape of epidermal cells of seeds and the presence of vesicle on the lateral walls of the epidermal cells of seeds.