Morphological characterization of natural populations of Onobrychis viciifolia (Leguminosae) from Central Italy

The intention of this work was to characterize natural populations of O. viciifolia by morphological traits, to investigate the variability among and within the populations and to deepen the understanding of the taxonomic elements that characterize the species. Twenty populations were used, twenty-one morphological characters were recorded. Each populations was found to be distinctly different from the others and well characterized by the morphological elements studied. A wide variability was also present both within and among populations. Different morphological forms were found to characterize different altitudinal zones: mountainous populations were clearly distinct from those of the foothills, while those coming from intermediate altitudes had intermediate characters. The differences among the three groups of populations did not have a clear line of demarcation. Being an allogamous species a clinal variation was found.