Comparative Anatomical Study of the Stems and Leaflets of Tribulus longipetalous, T. pentandrus and T. terrestris (Zygophyllaceae)

Abstract

In this study the anatomical characters of the stems and leaflets of T. longipetalous Viv., T. pentandrus Benth. and T. terrestris L. were compared to assist as a relevant source of information and contribute towards the standards to dispose the quality and identity of these plants to avoid adulterations. Transverse sections of the stems and leaf lets of the three species were done using wax method technique. The anatomical structures of the three studied species are very similar. The stems are formed of one layer epidermis, parenchymatous cortex, pericyclic fibers above the collateral vascular bundles, primary and secondary xylems and phloems, narrow medullary rays and wide parenchymatous pih. The densities of the epidermal hairs in the stems are found to be larger in T. pentandrus followed by T. longipetalous and lastly T. terrestris. There are sclrenchymatous fibres in the pith of T. longipetalous and T. pentandrus but not in T. terrestris. The leaflets are dorsiventral, showing kranz structure and different types of hairs. The densities of the epidermal hairs in the leaflets are found to be larger in T. longipetalous followed by T. pentandrus and lastly T. terrestris.