Trichioides iridescens, a new genus and new species (incertae sedis in Myxomycetes)

Abstract

A new monotypic myxomycete genus Trichioides, with type species T. iridescens, originating from the Northwestern Caucasus and Sakhalin Island is described, discussed and illustrated. In the absence of molecular sequence data, the genus Trichioides is temporarily placed in an incertae sedis position among Myxomycetes. This proposed enigmatic genus has morphological affinities with some genera of Trichiales and Liceales from the phylogenetic clade Lucisporidia, and shows the following unique combination of characters: a thick transparent gelatinous layer covering the whole sporocarp up to the final stage of sporogenesis; tubular, slightly curved, simple or forked bristle-like capillitium threads attached to the base of the sporotheca, sometimes to the inner surface of the peridium, ornamented by poorly or well-defined spiral bands; light greyish yellowish brown by transmitted light and smooth spores with spore wall of uniform thickness. Light and scanning electron micrographs of relevant morphological details are included.