Unearthing the identity, taxonomy and nomenclature of the enigmatic Marchantiopsis stoloniscyphula(Marchantiophyta, Marchantiaceae) from China

Owing to a combination of reportedly unique morphological characters and an unlocatable type specimen, Marchantiopsis stoloniscyphulahas been regarded as an enigmatic species in Marchantiaceae since its description, and all subsequent taxonomic treatments of this species were made without examination of the type. We located the original material of M. stoloniscyphulawhich was included as an admixture within the holotype of Wiesnerella fasciariadeposited in IFP. Our morphological examination found that M. stoloniscyphulaand W. fasciariaare conspecific with Marchantia papillatasubsp. grossibarbaand Sandea japonica, respectively. The nomenclature of Marchantiopsisand M. stoloniscyphulaare discussed. Lectotypes for M. stoloniscyphulaand W. fasciariaare also designated.