For a paper appearing in the Proceedings of the National Academy of Sciences, researchers at Clark University, Lawrence Berkeley National Laboratory's US Department of Energy Joint Genome Institute, and other international centers retrace the history of shiitake mushrooms and related mushrooms in the Lentinula genus. Based on genome sequences for 24 Lentinula individuals from eight Lentinula species and additional unnamed lineages, collected across four continents, the team flagged four main Lentinula clades going back millions of years in the Americas or Asia/Australasia. When the authors took a closer look at the shiitake species L. edodes by bringing in published short-read genome sequences for 60 isolates from China, they tracked down protein-coding genes within the L. edodes pangenome, while highlighting gene groups that appeared specific to wild mushroom populations. Together, the results suggest that L. edodes "comprises three independent lineages that may warrant recognition as species," they write. "One lineage of L. edodes is represented by a single Nepalese isolate, while the others are broadly distributed across East and Southeast Asia and show evidence of hybridization."