Morphological and Microscopic Characterization of Symphyotrichum squamatum (Spreng.) G.L. Nesom (Asteraceae) growing in Egypt

Symphyotrichum squamatum (Spreng.) G.L. Nesom, a member of the Asteraceae family, is native to South America and naturalized in Egypt. Species within the Asteraceae family, including those in the genus Aster, are characterized by the presence of various metabolites such as terpenes, phenolic compounds, peptides, and saponins. This study provides a comprehensive description of the plant's morphological and microscopical characteristics. The analysis revealed distinctive anatomical features, including cluster-type calcium oxalate crystals in the leaf tissues (measuring 9.40 µm to 13.8 µm in diameter), two types of stomata (primarily anomocytic and rarely paracytic, measuring 19.2 µm to 58.3 µm in length and 12.7 µm to 29.0 µm in breadth), as well as various types of fibers with different dimensions. The powdered stem is characterized by the presence fragments of lignified vessels, tracheids and tracheidal vessels. In contrast, the powdered root contained these elements along with wood fibers and fragments of cork with brownish contents. Calcium oxalate crystals were absent in both the stem and root.