An investigation of floral development in some Polygala taxa of Türkiye

In this study, the flower development of Polygala anatolica Boiss. & Heldr., P. monspeliaca L. and P. vulgaris L., species belonging to the Polygalaceae family, which naturally grows in Türkiye, was revealed by applying histological and scanning electron microscopy techniques. Flower development begins with the variation of the apical meristem into the floral meristem. The onset of the pistil primordia preceded the pistil primordia. Sections taken from different flower buds revealed that the ovules were orthotropic (atropous), produce two integuments, were bitegmic (double integuments), and appeared crassinucellate. These data indicated that the compared species showed no embryological differences. Scanning electron microscopy and stereomicroscopy revealed the formation of numerous irregularly indented and ridged areas on the petal surface, and the cuticle density increased as developmental stages progressed. The stigma lobes appeared distinct, the stamen filaments developed within sheaths attached to the corolla lobes, and the styles elongated significantly throughout the bud developmental stages. This study provides the first study of the floral development and characteristics of three Polygala species in Türkiye, providing embryological data for comparative systematic studies among related taxa.