Collaria spinifila sp. nov.: A new species of myxomycete from the urban environment of Shanghai, China

Abstract

The myxomycete genus Collaria has long received limited research attention and is frequently confused morphologically with the genera Comatricha and Lamproderma. During a myxomycete diversity survey in Shanghai, China, two distinctive specimens were obtained via moist chamber cultures of leaf litter collected from Gongqing National Forest Park. These specimens are characterized by an early-deciduous peridium leaving a distinct and persistent basal collar, a columella that terminates abruptly near the middle of the sporotheca and branches near its apex to form the capillitium, and capillitial threads bearing conspicuous spinose, dentate, or semi-annulate ornamentation at their free ends. Based on detailed morphological examination and a comprehensive comparison with all known species of both Collaria and Comatricha, this taxon is considered to represent a new species. Although attempts to obtain DNA sequences (nuclear 18S rDNA, translation elongation factor 1-alpha, and mitochondrial ribosomal small subunit RNA genes) using universal primers for dark-spored myxomycetes were unsuccessful, thereby preventing the determination of its molecular phylogenetic position, its stable combination of morphological characteristics aligns it more closely with the current concept of Collaria. Consequently, it is formally described here as the new species Collaria spinifila. Detailed photographic plates and a taxonomic discussion are provided.