A new hybrid of the genus Cirsium (Asteraceae) from Turkey: Cirsium × ovitense

This study presents a detailed description and analysis of Cirsium × ovitense, a new hybrid belonging to the genus Cirsium s.l. This hybrid was found in co-occurence between C. macrobotrys and C. vulgare and was examined in morphological, palynological and molecular aspects. The morphological investigation unveiled that the newly emerged hybrid displays certain intermediate characters compared to its parental species. The pollen morphology of C. × ovitense and its parental species underwent scrutiny using light microscopy (LM) and scanning electron microscopy (SEM). The pollen morphology of hybrid individuals was determined generally oblate-spheroidal (between 0.88 and 0.99) according to the P/E ratio, and the pollen grains were tricolporate. The molecular analyses encompass the scrutiny of nuclear ribosomal DNA (ITS) data from all collected samples. Molecular results show that C. × ovitense has some polymorphic nucleotide regions in their nuclear ITS genomes and the hybrid is located more closely to C. macrobotrys. Furthermore, statistical analyses that considered macro- and micro-morphological characters demonstrated the hybrid’s closer similarity to C. macrobotrys. The results obtained from this study also include evidence supporting the hybridization phenomenon within Cirsium.