ABSTRACT
Among the numerous species of the family Euphorbiaceae the photosynthetic carbon fixation follows three pathways: C3, C4, CAM. The object of the present research was Euphorbia peplis L., grown and collected on a Mediterranean coast. Leaf anatomy and ultrastructure together with carbon isotope discrimination measurements indicated that E. peplis is ascribable to the NADP-malic enzyme C4 photosynthetic type.