Morphological and phylogenetic analyses reveal taxonomic insights in Marasmiaceae, including ten new species from Northeast China Ecological Region

Based on morphological characteristics and phylogenetic analyses using ITS, nrLSU, rpb 2, and tef 1-α sequence data, six new species belonging to subg. Globulares were identified and described. In addition, this study addressed the taxonomic confusion surrounding ser. Haematocephali through detailed discussions. Two new species were documented in Marasmius subg. Marasmius . Furthermore, Cr. nigricaulis var. macrospora was raised to species rank as Cr. macrospora , and one new species each of Crinipellis and Moniliophthora was described. Within Marasmiaceae , the subfamily names Marasmieae and Crinipellieae are corrected to Marasmioideae and Crinipelloideae , respectively. Cr. xiaoxinganlingensis nom. prov., with an uncertain systematic position, was also incorporated into Crinipellis . Accordingly, this genus is of great significance in resolving the taxonomic framework of Crinipelloideae . By compiling and discussing habitat information for the relevant species, this study further emphasized the value of ecological evidence for clarifying taxonomic boundaries and evolutionary relationships among genera. Moreover, by synthesizing diagnostic characters, clearer and more practical identification keys were constructed at multiple taxonomic levels, including the generic level within Marasmiaceae and the subgeneric, sectional, subsectional, and series levels within Marasmius . These findings have also substantially enriched the species diversity of Marasmiaceae in the Northeast China Ecological Region.