ANATOMICAL FEATURES OF SIX ONOSMA L. (BORAGINACEAE) SPECIES FROM TURKEY

In the present study, Onosma discedens Hausskn. & Bornm., Onosma tenuiflora Willd., Onosma aucheriana DC., Onosma roussaei DC., Onosma rigida Ledeb. and Onosma trapezuntea Boiss. & A.Huet ex Hand.-Mazz. were examined by light microscopy (LM) in terms of stem and leaf anatomy. The anatomical characters were numerically analyzed by cluster analysis (CA) and principal component analysis (PCA). Although general stem and leaf anatomical traits are very similar, some anatomical characters such as the ratio of cortex/diameter of stem and phloem/xylem, the average row number of collenchyma, palisade and spongy cells, and stomata index are more important for delimiting the investigated taxa. These results indicated that anatomical features would be useful in separating the examined species