Marasmius campestris sp. nov. (Marasmiaceae, Agaricales) from tropical China based on morphological and molecular evidence

Marasmius campestris (Marasmiaceae, Agaricales), a member of sect. Globulares, is described as a new species from Hainan Island, a tropical region of China. It is morphologically characterized by an umbilicate, deeply sulcate and striped, purple-tinged pileus, a stipe covered with tiny scales, large basidiospores, well-developed cheilocystidia with irregular shape, a pileipellis consisting of Globulares-type cells, and growth in grassland. The phylogenetic analyses of DNA sequences from nuc rDNA internal transcribed spacer (ITS) also confirm that it forms an independent lineage within Marasmius. Consequently, a description, color photos of fresh basidiomata and line-drawings of microstructures are presented.