Rediscovery of Cyathus badius, an 'extinct' species from the Bonin Islands, Japan

The Bonin Islands, Japan, present a unique and endemic fauna and flora, however a large portion of these species, including fungi, are now considered endangered or extinct. During almost 80 y Cyathus badius was included in that statistics and no additional collections were recorded until a new expedition in 2015. Morphological comparisons with the holotype are consistent with the new specimen, and phylogenetic analyses based on ribosomal ITS, LSU and concatenated dataset placed C. badius in a highly supported clade with C. parvocinereus. Is proposed here to epitypify C. badius with illustrations, new morphological characters and DNA data.