Morphological and anatomical studies of iinvolucral bracts(Phyllaries) in some species of Centaurea L. of family Asteraceae in Iraq

Abstract

Involucral bracts usually considered a diagnostic characters of Asteraceae .In the current research the morphologicaland anatomical characteristics of the involucral bracts were examined in 24 species of Centaurea . L. The morphological features included the general shape of involucre,dimentions ,number of rows ,colors and theindumentums,more than the presence or absence of peduncle ,as well as the presence or absence of appendeges forthe phyllaries and their nature ,colors and site.All these characteristics showed great taxonomic importance anddiscussed.The characteristics which included shape of anticlinal walls of epidermis ,types of stomata ,they haveproved to be of great importance in separating the species from each other