The overwhelming majority of described fungal species are members of the subkingdom Dikarya (Hibbett et al. 2007), which is composed of the two phyla Ascomycota and Basidiomycota. The life cycles of most basidiomycetes include long-lived dikaryotic hyphae (i.e., hyphae in which cells contain a haploid nucleus from each parent rather than a single haploid or diploid nucleus), with the periodic production of fruiting bodies known as basidiocarps (the basidiocarps of many species are commonly referred to as "mushrooms"). Basidiomycota includes around 32,000 described species (Kirk et al. 2008).
Basidiomycota is divided into three subphyla:
1) Pucciniomycotina: Most of the species in this group are parasitic plant rusts (Aime et al. 2006).
2) Ustilaginomycotina: The vast majority of species in this group, often known as smut fungi, are parasites of angiosperms [flowering plants], mainly grasses and sedges (Begerow et al. 2006).
3) Agaricomycotina: This group includes around a third of the described species of Fungi, including mushrooms, jelly fungi (Millanes et al. 2011), and basidiomycetous yeasts (Fell et al. 2000; Scorzetti et al. 2002). There are around 21,000 described species of Agaricomycotina, which is around two thirds of known Basidiomycota (Kirk et al 2008). The Agaricomycotina includes many wood decayers, litter decomposers, and ectomycorrhizal fungi, along with relatively small numbers of important pathogens of timber, vegetable crops, and humans. Some Agaricomycotina are highly poisonous to humans, while others are hallucinogenic or edible. Edible species include cultivated saprotrophs (e.g., Agaricus bisporus and the Shiitake, Lentinula edodes) and field-collected mycorrhizal species (e.g., the chanterelle Cantharellus cibarius, the bolete Boletus edulis, and the Matsutake Tricholoma matsutake). Some species produce enormous fruiting bodies (e.g., the polypores Bridgeoporus nobilissimus in the Pacific Northwest of the United States, Fomitiporia ellipsoidea in China, and Rigidoporus ulmarius in Europe) or vast and long-lived underground mycelial networks (e.g., Armillaria ostoyae). (Hibbett 2006 and references therein)
Zhao et al. (2008) provide an overview of recent work on understanding phylogenetic relationships within the Agaricales, a major group within the Agaricomycotina that is the largest clade of mushroom-forming fungi (Matheny et al. 2006 and references therein).
