Morphological and anatomical study of the genus Sambucus L. (Adoxaceae) in Iran

Sambucus (Adoxaceae) is a tall tree-like shrub distributed throughout temperate and subtropical regions in Europe, Asia, North Africa and North America. Since there is not any morphological and anatomical comprehensive study on Sambucus species in Iran and Sambucus nigra is located in the Arasbaran region with very limited distribution, we have encouraged studying the patterns of morphological variation and anatomical structure among Sambucus taxa. In this study, the morphological and anatomical structure of 18 populations from two species of Sambucus (S. ebulus and S. nigra) has been considered to evaluate the relationships in this genus. In total, nine quantitative and nine qualitative morphological features were evaluated and measured. Ward’s dendrogram showed two main clusters. The first cluster is composed of a population of S. nigra. The second cluster was composed of two subsets and contained populations of S. ebulus in Golestan, Mazandaran and Gilan provinces. There were two types of epidermal cells, puzzle-shaped in S. ebulus and oblong cells in S. nigra. The stems are rounded shape in both species. The margin is quite wavy in S. ebulus and straight in S. nigra. Both species showed a rounded shape with a wavy margin in petiole cross-sections. Pedicel cross-sections of both species are similar to each other in the general shape of cross-sections and margins. Both are rounded in shape and the margin is quite sinuous shapes in S. ebulus and wavy in S. nigra. The present study showed that a combination of morphological and anatomical data provides reliable evidence for the differentiation of two species of S. nigra and S. ebulus.