Shiitake mushrooms get their name from the same place they often source their nutrients — the shii tree, a Japanese relative of the oak. These fungi are part of the genus Lentinula, which have evolved to decompose hardwoods on every continent besides Europe and Antarctica. Lentinula mushrooms are white rot fungi, belonging to an elite group of decomposers that can break down all of wood’s components — cellulose, hemicellulose, and the toughest molecule, lignin. Understanding Lentinula genomes and their evolution could provide strategies for converting plant waste into sugars for biofuel production. Additionally, these fungi play a role in the global carbon cycle. As decayers, Lentinula fungi access carbon previously locked away in wood, converting it into their own carbon-rich structures, as well as atmospheric carbon dioxide.