[3] More specifically, Basidiomycota includes these groups: agarics, puffballs, stinkhorns, bracket fungi, other polypores, jelly fungi, boletes, chanterelles, earth stars, smuts, bunts, rusts, mirror yeasts, and Cryptococcus, the human pathogenic yeast.

Basidiomycota are filamentous fungi composed of hyphae (except for basidiomycota-yeast) and reproduce sexually via the formation of specialized club-shaped end cells called basidia that normally bear external meiospores (usually four).

Basidiomycota that reproduce asexually (discussed below) can typically be recognized as members of this division by gross similarity to others, by the formation of a distinctive anatomical feature (the clamp connection), cell wall components, and definitively by phylogenetic molecular analysis of DNA sequence data.

A 2007 classification, adopted by a coalition of 67 mycologists recognized three subphyla (Pucciniomycotina, Ustilaginomycotina, Agaricomycotina) and two other class level taxa (Wallemiomycetes, Entorrhizomycetes) outside of these, among the Basidiomycota.

[5] As now classified, the subphyla join and also cut across various obsolete taxonomic groups (see below) previously commonly used to describe Basidiomycota.

[6] Wijayawardene et al. 2020 produced an update that recognized 19 classes (Agaricomycetes, Agaricostilbomycetes, Atractiellomycetes, Bartheletiomycetes, Classiculomycetes, Cryptomycocolacomycetes, Cystobasidiomycetes, Dacrymycetes, Exobasidiomycetes, Malasseziomycetes, Microbotryomycetes, Mixiomycetes, Monilielliomycetes, Pucciniomycetes, Spiculogloeomycetes, Tremellomycetes, Tritirachiomycetes, Ustilaginomycetes and Wallemiomycetes) with multiple orders and genera.

[7] Traditionally, the Basidiomycota were divided into two classes, now obsolete: Nonetheless these former concepts continue to be used as two types of growth habit groupings, the "mushrooms" (e.g. Schizophyllum commune) and the non-mushrooms (e.g. Mycosarcoma maydis).

[3] The Agaricomycotina include what had previously been called the Hymenomycetes (an obsolete morphological based class of Basidiomycota that formed hymenial layers on their fruitbodies), the Gasteromycetes (another obsolete class that included species mostly lacking hymenia and mostly forming spores in enclosed fruitbodies), as well as most of the jelly fungi.

This sub-phyla also includes the "classic" mushrooms, polypores, corals, chanterelles, crusts, puffballs and stinkhorns.

[9] The class Wallemiomycetes is not yet placed in a subdivision, but recent genomic evidence suggests that it is a sister group of Agaricomycotina.

These include: Unlike animals and plants which have readily recognizable male and female counterparts, Basidiomycota (except for the Rust (Pucciniales)) tend to have mutually indistinguishable, compatible haploids which are usually mycelia being composed of filamentous hyphae.

[citation needed] The maintenance of the dikaryotic status in dikaryons in many Basidiomycota is facilitated by the formation of clamp connections that physically appear to help coordinate and re-establish pairs of compatible nuclei following synchronous mitotic nuclear divisions.

Ballistic basidiospores are formed on sterigmata which are tapered spine-like projections on basidia, and are typically curved, like the horns of a bull.

The ability of C. neoformans and M. maydis to undergo meiosis may contribute to their virulence by repairing the oxidative DNA damage caused by their host's release of reactive oxygen species.

In the human pathogenic genus Cryptococcus, four nuclei following meiosis remain in the basidium, but continually divide mitotically, each nucleus migrating into synchronously forming nonballistic basidiospores that are then pushed upwards by another set forming below them, resulting in four parallel chains of dry "basidiospores".

This stage, numbered "0", produces single-celled spores that ooze out in a sweet liquid and that act as nonmotile spermatia, and also protruding receptive hyphae.

On the primary host a repeating spore stage is formed, numbered "II", the urediospores in dry pustules called uredinia.

It does not continue the infection process, rather it remains dormant for a period and then germinates to form basidia (stage "IV"), sometimes called a promycelium.

In other smuts, such as Tilletia caries, the elongated haploid basidiospores form apically, often in compatible pairs that fuse centrally resulting in H-shaped diaspores which are by then dikaryotic.

[citation needed] Smuts with both a yeast phase and an infectious hyphal state are examples of dimorphic Basidiomycota.

[17] In plant parasitic taxa, the saprotrophic phase is normally the yeast while the infectious stage is hyphal.

Examples are Collybia tuberosa[20] with its apple-seed-shaped and coloured sclerotium, Dendrocollybia racemosa[21] with its sclerotium and its Tilachlidiopsis racemosa conidia, Armillaria with their rhizomorphs,[22] Hohenbuehelia[23] with their Nematoctonus nematode infectious, state[24] and the coffee leaf parasite, Mycena citricolor,[22] and its Decapitatus flavidus propagules called gemmae.