Importance of type specimen study for understanding genus boundaries—taxonomic clarifications in Lepidoderma based on integrative taxonomy approach leading to resurrection of the old genus Polyschismium

ABSTRACT

Type specimens of four species of Lepidoderma (Myxomycetes, Amoebozoa)—L. crassipes, L. neoperforatum, L. perforatum, and L. stipitatum—have been studied using an integrative approach including application of traditional taxonomy methods, i.e., morphological study under stereoscopic and compound microscopes, detailed analysis of micromorphological characters using scanning electron microscopy, and molecular analysis by way of Sanger sequencing of molecular markers (nuc 18S rDNA and elongation factor 1-alpha gene, EF1A). Results of the study revealed that L. crassipes is conspecific with L. tigrinum, L. stipitatum is a malformed specimen of Diderma floriforme, whereas L. perforatum and L. neoperforatum represent two well-defined morphologically and genetically separate species. Phylogeny of Physarales shows the polyphyletic character of the genus Lepidoderma. The type species of Lepidoderma clusters together with Diderma, whereas other representatives of this genus form a monophyletic, well-supported clade. The species from this clade are proposed to belong to the genus Polyschismium described by A. Corda in 1842 that is resurrected and emended here. Nine species of Lepidoderma are transferred to Polyschismium. A new key to Didymiaceae including Polyschismium is provided.

KEYWORDS:

• 18S rDNA
• Amoebozoa
• EF1A
• Myxogastria
• Myxomycetes
• phylogeny
• protists
• SEM
• taxonomy
• 9 new taxa

ACKNOWLEDGMENTS

We thank Anna Drozdowicz and Wolfgang Nowotny for providing us their specimens used in this study; curators of BM, E, and K for their help in location of original material of L. trevelyanii; Renée Skrzypczak, Henrik F. Gøtzsche, and Lee Davies (K) for loan of additional specimens used in this study; Adam T. Halamski for consultation of Latin; Paweł Kapusta for assistance in statistical analysis; Paulina Sulima-Samujłło for taking macrophotographs of Lepidoderma neoperforatum and L. perforatum; Krzysztof Stachowicz and Jolanta Urbanik for taking macrophotographs of L. trevelyanii; Anna Łatkiewicz for her help with SEM images of L. neoperforatum and L. perforatum; and Mariusz Wierzgoń for bryological consultation.

SUPPLEMENTARY MATERIAL

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00275514.2022.2109914.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research received support from the SYNTESYS+ project (www.synthesys.info) granted to Anna Ronikier (BE-TAF 152), that is a DiSSCo (Distributed System of Scientific Collections) project financed by Horizon 2020 Research Infrastructures Programme, and from the statutory fund of the W. Szafer Institute of Botany, Polish Academy of Sciences.