ANATOMICAL STUDY OF THE STEMS OF SOME WILD SPECIES OF POACEAE FAMILY IN THE WESTERN DESERT

Abstract

Abstract The research included anatomical study of cross sections of stems of eight species belonging to six genera, namely Aristida adscensionis, Avena barbata, Avena fatua, Eragrostis cilinensis, Polypogon monseplinsis, Schismus arabicus, Setaria glauca, Setaria verticillata from plants of the Poaceae family growing in the Western Desert of Iraq. The results showed that the quantitative and qualitative characteristics have greatly contributed to isolating the species depending on the cross-sectional diameter of the stem, which ranged between 1112-2185 μm. The sections also varied in terms of the presence of the core region (soild section) or the absence of it (hollow section). As for the sclerenchymal tissue, its cell numbers ranged between 2-9 rows, as well as the variation in thickness of this tissue between species. The same is the case with the Parenchyma tissue, which differed greatly between the types in terms of thickness and the type of tissue, which ranged between the ordinary Parenchymal tissue and the Chlorenchyma tissue, as well as the variation in the nature of the tissue between the regular annular and semi-annular or in the form of small, medium or large clusters. Most types contained two or three rows of bundels except for Avena barbata and Avena fatua, which contained only one row. The number of vascular bundles varied greatly between species, as well as their different in sizes and the different diameter of a single vessel.