NOTES ON LEAF AND STEM ANATOMY OF Thlaspi Sensu Lato

In this study, anatomical characteristics of leaves and stems of 19 taxa of Thlaspi sensu lato, 9 of which are endemic to Turkey, were investigated in order to determine taxonomic relationships among the studied taxa. The anatomical characteristics of all taxa were determined and assessed using the cluster analysis and the principal component analysis. The transverse sections of the leaves and stems exhibited various diagnostic characters in terms of the pattern of epidermal cell and mesophyll layers, the number and size of vascular bundles, and the thickness of the cortex and endodermis. Important differences were detected in number, size, and index of stomata, and in epidermal cell wall structures in the adaxial and abaxial surfaces. The results showed that the compared anatomical characteristics among taxa are partially compatible with their sectional delimitation in their traditional rank in The Flora of Turkey and the East Aegean Islands. The results also point out that some taxonomic re-arrangements may be required.