Pollen morphology of the genus Cota J. Gay (Asteraceae) in Turkey

Abstract

Pollen morphology of 22 Cota taxa naturally distributed in Turkey was investigated to describe their pollen features and to evaluate the diagnostic value of pollen characters for systematic purposes using light microscopy and scanning electron microscopy. Pollen grains of Cota are radially symmetrical and isopolar. Their shape is oblate-spheroidal with the polar axes 21.6-34.56 mu m and the equatorial axes 23.04-33.6 mu m. The pollens are trizonocolporate. The outline is elliptic in equatorial view and triangular in polar view; amb intersemiangular. Exine sculpturing is echinate. Inter-spinal region exhibits perforate and microreticulate-perforate ornamentations. Numerical analysis revealed that dimensions of the pollen grains and surface ornamentation are the most reliable characters for delimiting the taxa within the genus.