A novel variant devoid of rayflorets was identified in the interspecific derivatives of the cross between cultivated sunflower and H. divaricatus. The outermost whorl of the capitulum was comprised of modified disc florets which had longer petals than the regular disc florets and were hermaphrodite unlike the ray florets which are unisexual with non-functional stigmas. Inherit ance studies indicated that the apetalous trait is under monogenic recessive gene control. Utility of the trait in physiological and breeding studies is under investigation.