Natural hybridization and introgression in sympatric Ligularia species (Asteraceae, Senecioneae)

The difficulty in clarifying species of genus Ligularia Cass. has been attributed to rapid and continuous allopatric speciation in small and isolated populations, combined with interspecific diploid hybridization in the Qinghai‐Tibetan Plateau and adjacent areas. However, no concrete example has been reported to prove this hypothesis. We studied a natural mixed population of six species of Ligularia in which some individuals were morphologically...