The Russulaceae are a diverse family of fungi in the order Russulales, with roughly 1,900 known species and a worldwide distribution. They include the genus Russula and the milk-cap mushrooms, some of which are edible. Russulaceae have gilled mushrooms characterised by brittle flesh. In addition to these typical agaricoid forms, the family contains species with fruitbodies that are laterally stiped (pleurotoid), closed (secotioid or gasteroid), or crust-like (corticioid). Molecular phylogenetics has demonstrated close affinities between species with very different fruitbody types and has discovered new, distinct lineages. An important group of root-symbiotic Russulaceae fungi in forests and shrublands around the world includes Lactifluus, Multifurca, Russula, and Lactarius. The crust-forming genera Boidinia, Gloeopeniophorella, and Pseudoxenasma, all wood-decay fungi, have basal positions in the family. (Full article...)