The stem and leaf anatomy of the ten species of Jasione L. (Campanulaceae) in the Iberian Peninsula were investigated; their infra-specific taxa were also studied. The species differ from each other anatomically and can be identified by their anatomical characters. The anatomical evidence supports the taxonomic treatment that will be published in the forthcoming Flora iberica Volume 14. The possible relations between the anatomy and the ecology of these plants are discussed. Specialized small multicellular structures (trichoids) present on the leaf surface, whose interest has not previously been recognized, are described and their possible function discussed.