What do leaf anatomy and micro-morphology tell us about the psammophilous Pancratium maritimum L. (Amaryllidaceae) in response to sand dune conditions?

The present study aimed at verifying the morphological variation in leaf traits among different popu-lations of Pancratium maritimum (sea daffodil) and the correlation between leaf diversity and climateconditions at different sites. Eleven populations of P. maritimum from Mediterranean coastal sand duneswere investigated with respect to leaf surface micro-morphology, leaf anatomy, and vascular pattern. Morphometric analysis was based on 29 quantitative foliar parameters. One-way analysis of variance(ANOVA), principal component analysis (PCA), discriminant function analysis (DFA), and clustering byWard’s method were used for the statistical evaluation. Results revealed a rather uniform leaf structurein P. maritimum, but many significant differences were detected among the studied populations. Theobserved population variation in leaf traits reflects an important phenotypic plasticity among popula-tions of P. maritimum associated with different local climatic regimes that may facilitate plant survivalunder stressed environmental conditions of sand dunes. The most sensitive morpho-anatomical traitsin P. maritimum, which express leaf phenotypic plasticity, are leaf outline and venation, leaf thickness,stomata distribution, and size. Our results indicate that the modifications of leaf architecture are impor-tant anatomical and physiological strategies to help P. maritimum reducing water loss through leaves andincreasing water use efficiency.