Distribuzione e variabilità del genere Arbutus L.: analisi sistematica e morfologia integrata di Arbutus unedo L. in Sardegna

In this study, systematic of <i>Arbutus</i> was examined in literature, by investigating the number, distribution and diagnostic characters of its species. Then, the place names in Sardinian language meaning †œStrawberry Tree†� were identified, to make a distribution map of these localities in Sardinia. Finally, morphological variability of four populations of Strawberry Tree (<i>Arbutus unedo</i> L.) growing in four areas of Sardinia, with different geolithological conditions, was assessed. Morphometric analysis, based on eleven morphological traits, was performed on three leaves and three fruits per plant, sampled from thirty plants per population. Standard biometric methods were used for leaf and fruit physiognomy, and a geometric morphometric approach used for leaf conformation. Statistical multivariate analysis showed significant differences between populations (p<0.05) and high discrimination percentages. The most important discriminating traits were: petiole length, leaf width, ratio between distal part and total lamina length, fruit length, fruit width, and ratio between fruit length/fruit width. Climatic differences among the four areas and significant correlations between morphological traits and ecological parameters were found. In conclusion, environment plays an important role in the observed variations, so populations can be considered different. Based on the literature and fieldwork carried out, new forms and a variety of <i>Arbutus unedo</i> were found for the first time in Italy.