Comparative anatomical and ecological investigations on some Centaurea (Asteraceae) taxa from Turkey and their taxonomic significance

The anatomical and ecological characteristics of 7 centaurea l. s. l. taxa (c. urvillei dc. ssp. stepposa wagenitz,c. pseudoreflexa hayek,c. simplicicaulis boiss. & huet,c. pecho albow,c. hypoleuca dc.,c. cheiranthifolia willd.var. purpurascens (dc.) wagenitz,c. woronowii bornm.),which three of them are endemic (c. pseudoreflexa,c. pecho,c. woronowii) to turkey has been carried out. cross sections of stem,leaf blade and midrib and peripheral sections of the leaves,and ph,total n,p,k and organic matter contents of soil samples have been investigated. variance analysis and tukey's honest significant difference test were performed on ecological and anatomical data. ecological characteristics obtained in this investigation were found mostly similar. on the other hand,anatomically important differences were determined in diversity of anticlinal cell walls,length and width of abaxial epidermis,number of bundles in the midrib and number of stomata per mm2 both on the epidermis of the leaf,and the shape of transverse section of stem. according to tukey's honest significant difference test,especially length and width of abaxial epidermis,number of stomata both on the adaxial and abaxial epidermises have displayed three distinct groups. these results are in accordance with sectional delimitation in the flora of turkey and also support upgrading the sum of species of the genus centaurea.