Comparative leaf and petiole anatomy and micro morphology of the genus Geum (Rosaceae) from Iran

In the present study leaf anatomical and micro morphological characters of 5 species of Geum L. belonging to two subgenera Orthostylus and Geum were studied using light (LM) and scanning electron microscopy (SEM). For anatomical analysis, cross section of basal leaves and their petioles were prepared. The best sections were selected for staining and their photograph were taken. For micro morphological study, leaf and petiole pieces were washed and dried, then prepared for scanning electron microscope. Anatomical and micro morphological characters were carefully examined and measured. The result revealed taxonomically valuable anatomical (glandular hairs, number of epidermal cell around stoma and types of vascular bundle in blade; shape of crust cell, vascular bundle pattern and shape of cross section in petiole) and micro morphological evidences (trichome length, epicuticular was sculpturing, distribution of wax on outer, inner and peristomatal rim and stomata ledge aperture in blade; presence or absence of hairs and their direction, epicuticular was sculpturing types of petiole). These characters are useful for separating the two subgenera and their species. Our findings support the current classifications. An identification key was presented based on the diagnostic studied characters.