Contributions to the taxonomy of Periplocoideae and Asclepiadoideae (Apocynaceae) in Türkiye based on fruit and seed morphology

In this study, the fruit and seed morphology of all the Periplocoideae (Periploca gracilis and P. graeca) and the majority of Asclepiadoideae (Araujia sericifera, Cionura erecta, Cynanchum acutum and Gomphocarpus fruticosus) taxa in Türkiye was evaluated from a taxonomic point of view using, for the first time, both light and scanning electron microscopy. Macro- and micro-morphological investigations were carried out on herbarium samples. An identification key for the examined Periplocoideae and Asclepiadoideae taxa, and expanded fruit and seed descriptions for each taxon were prepared. Numerical analysis showed that shape and size of follicle, size, shape and surface texture of seed were found to be effective in delimiting the studied Periplocoideae and Asclepiadoideae taxa at subfamilial and generic levels.