Influence of Illumination Conditions on the Color and Structure of the Peridium of Nannangella alpina (Physarales, Myxomycetes)

Myxomycetes are one of the examples of fungus-like protists with hidden diversity. Their trophic stages are usually hidden from the eye. The species is identified based on the characteristics of mature sporulation. Morphological characteristics, including the structure and color of the peridium and capillitium as well as belonging to a certain ecological and trophic group, are issue of important value. In August 2024, ten specimens were found in the vicinity of Krasnoufimsk (Sverdlovsk Region, Russia), which were classified as Nannangella alpina (= Physarum alpinum) based on morphological characteristics. They were shown to have variable color and structure of the peridium depending on the illumination of the substrate on which the sporulation was found. The reliability of the identification of the collected specimens and the taxonomic history of the species are discussed. Based on the variability of morphological and ecological characteristics, it can be assumed that either this morphospecies is highly variable, or N. alpina is a group of cryptic species of different ecology.