Abstract:
The anatomical characteristics of two endemic species viz., Onosma halophila Boiss. & Heldr. and O. mollis DC. were investigated. Both of examined species are Iran-Turan Element. The root of examined species observed as secondary structure and cortex is multilayered. Raphide crystals were observed in epidermis and 2-3 layered of cortex cells bellow epidermis in O. mollis. leaves are isobilateral (=equifacial) in both species. Cystoliths were seen basal portions of hairs on both side epidermis of leaves in two species. Stomata types were anisocytic and anomocytic in both species. The stomata index is 11.18 of upper epidermis and 10.71 of lower epidermis in O. mollis. The stomata index is 10.95 of upper epidermis and 12.67 of lower epidermis in O. halophila. Vascular bundles were surrounded by a parenchymatic sheat in both species.
