Morphological variation of Juniperus oxycedrus subsp. macrocarpa (Cupressaceae) in three Italian localities

Abstract

The intra- and interpopulational geographic variation of three distant populations of J. oxycedrus subsp. macrocarpa was examined biometrically on the basis of morphological key-characters of needles, seeds and cones. The shortest Euclidean distances were used in the agglomerative grouping of closest neighbourhood and discrimination analysis with principal component analysis (PCA) was performed to verify the south-north differentiation of the taxon in Italy. Most of the cone and seed dimensional characters are correlated. No significant correlations were found between cone and needle characters. The sampled populations differ only insignificantly from one another, while the intrapopulational variation is slightly higher. Cone length as well as seed number, width and thickness were significantly correlated with geographic latitude, while the other four characters are not. Differences in cone shape were observed between individuals, so that several morphotypes can be distinguished.