Johannes Paulus Lotsy

The Russulaceae are a diverse family of fungi in the order Russulales, with roughly 1,900 known species and a worldwide distribution. They comprise the brittlegills and the milk-caps, well-known mushroom-forming fungi that include some edible species. These gilled mushrooms are characterised by the brittle flesh of their fruitbodies. In addition to these typical agaricoid forms, the family contains species with fruitbodies that are laterally striped (pleurotoid), closed (secotioid or gasteroid), or crust-like (corticioid). Molecular phylogenetics has demonstrated close affinities between

The Hygrophoraceae are a family of fungi in the order Agaricales. Originally conceived as containing white-spored, thick-gilled agarics (gilled mushrooms), including Hygrophorus and Hygrocybe species (the waxcaps or waxy caps), DNA evidence has extended the limits of the family, so it now contains not only agarics, but also basidiolichens and corticioid fungi. Species are thus diverse and are variously ectomycorrhizal, lichenized, associated with mosses, or saprotrophic. The family contains 34 genera and over 1000 species. None is of any great economic importance, though fruit bodies of some

The Paxillaceae are a family of mushroom-forming fungi bearing close affinity to the boletes. Collectively, the family contains nine genera and 78 species. The type genus is Paxillus, containing fungi with decurrent gills, and Gyrodon, which has members with decurrent pores, among others. French mycologist René Maire had erected the family in 1902, placing it between the agarics and boletes and recognizing the groups' similarities with the latter group. Maire's usage of the name was later deemed to be invalid, and the genus authority is attributed to Johannes Paulus Lotsy. Molecular research

The Fistulinaceae are a family of fungi, the best-known member of which is the beefsteak fungus Fistulina hepatica. Molecular studies have now shown it to lie within the Agaricales.

The Peniophoraceae are a family of fungi in the order Russulales. Species of this family have a cosmopolitan distribution and are mostly saprobic, causing rots of standing and fallen wood. According to 2025 data the family contains 16 genera and 416 species.