Anatomy of four taxa of the genus Juniperus sect. Juniperus (Cupressaceae) from the Balkan Peninsula

The aim of this research was to describe variability of anatomical characteristics of needles and stems of the taxa: J. communis subsp. communis var . communis, J. communis subsp. communis var. intermedia Sanio, J. communis subsp. alpina (Suter) Čelak and J. deltoides Adams, from Serbia, Montenegro and Macedonia (Balkan Peninsula), to establish whether anatomical differences are influenced by the phylogenetic or ecological position of individual taxa. Macroscopic and microscopic analyses were done on samples of 13 populations from Eu- Mediterranean coastal areas of up to 2,000 m a.s.l. in continental mountains. Descriptive statistics were calculated for 23 quantitative characters. Canonical Discriminant Analysis (CDA) and clustering on the basis of the UPGMA method were performed to measure distances between the groups. At an anatomical level there was fine differentiation between the taxa, at the level of species and subspecies. The species J. communis and J. deltoides differed in number of stomatal bands, needle cross-sectional shape, dimensions of the needle resin duct, as well as in the structure of the central cylinder in the primary structure of the stem. Within the species J. communis, high mountain subspecies J. communis subsp. alpina was finely differentiated compared with the typical subspecies J. communis subsp. communis. Basic differences between these two taxa were refl ected in the shape and dimensions of the needles. Discriminant and cluster analyses did not show any major differences between J. communis subsp. communis var. communis and J. communis subsp. communis var. intermedia. Multivariate analysis showed that the level of anatomical differentiation of these taxa were conditioned partially by phylogenetic association of individual taxa, and partially by ecological conditions of the habitat. Our results showed that anatomical characteristics of needle and primary structures of the stem of these species of genus Juniperus have taxonomic signifi cance at the species and infraspecies levels.