Comparative Anatomy, Pollen and Seed Morphology of Two Verbascum Varieties (Scrophulariaceae) and Their Taxonomic Significance

Abstract

In this study, the anatomical, palynological, and seed micromorphological traits of two Verbascum varieties found in the Southeastern Anatolia Region were investigated. These variations are V. sinuatum subsp. sinuatum var. adenosepalum Murb. and V. sinuatum subsp. sinuatum var. sinuatum L. Cross-sections from the taxa's roots, stems, and leaves were viewed under a light microscope for anatomical study. The xylem components play a significant role in the taxonomic root portions. The pith area is a broad region in stem sections, and the upper portion of the epidermis cells is encircled by a distinct indented cuticle layer. The leaves' primary vein is represented by open collateral bundles. Pollen grains in Verbascum sinuatum subsp. sinuatum var. adenosepalum are tricolporate-tricolpate, prolate-spheroidal, and have reticulate exine ornamentation. Similarly, pollen grains in V. sinuatum subsp. sinuatum var. sinuatum are tricolporate-tricolpate, prolate, and have reticulate exine ornamentation. The brown seeds of V. sinuatum subsp. sinuatum var. adenosepalum and V. sinuatum subsp. sinuatum var. sinuatum have an alveolate, deep and wide posterior region, a truncated beak, and a prismatic-oblong shape. The ornamentation of the seed coat is made up of irregular polygonal cells that have noticeable and dense vesicles. The importance of a few traits in the Verbascum variety delimitation has been investigated in this study. For the purpose of supporting ancestral traits in the infrageneric classification and helping with genus systematics, some pollen and seed characters which are typically connected to pollen and seed micromorphological and anatomical patterns can be applied.