Morpho-functional adaptations inCakile maritimaScop. subsp.maritima: comparation of two different morphological types

Abstract

Along the Italian maritime foredunes there are two different morphotypes of Cakile maritima Scop. subsp. maritima differing in leaf shape: one type is characterized by entire lamina, while the other one shows pinnatifi d leaves. Therefore, this study was performed to analyze leaf morpho-functional characters of both C. maritima morphotypes in order to highlight the peculiar adaptations to the ecological conditions of sand dune environments and to compare the two different morphological types. The morpho-functional traits analyzed are leaf roll, general morphology of epidermis, vesicular cells, salt crys- tals, stomatal apparatus, stomatal density (SD), hydathodes, mesophyll, idioblasts, specifi c leaf area (SLA) and leaf dry matter content (LDMC). The most interesting anatomical adaptations to sand dune habitats are thick epidermal cuticle; high stomatal density; epidermal vesicular cells involved in water storage, sunlight refl exion and together with hydathodes in salt elimination; high development of palisade and water storage parenchyma; bundle sheath typical of C 4 leaf anatomy. Differences in several leaf characters between the two morphotypes seem to suggest that pinnatifi d morphotype is more resistant to stress and environmental disturbance than the entire type. The analysis of C. maritima distribution in two different coastal traits affected by progradation or erosional processes confi rmed this hypothesis.