Basidiomycota

The Basidiomycota is the second largest phylum in the kingdom Fungi with about 53,000 species that are commonly called basidiomycetes. This is also the most conspicuous kingdom since it includes mushrooms, bracket fungi, puffballs, and other large fruiting bodies. The kingdom also includes some yeasts, as well as two groups of important plant pathogens, the rust fungi, and the smut fungi. 

Sexual Reproduction in the Basidiomycota

The sexual spore in this phylum is the basidiospore. Basidiospores are produced from a club-like structure called a basidium (pl. basidia). Typically, four basidiospores are produced externally on each basidium. The basidiospores are unicellular and each spore is formed at the tip of a small pointed projection called a sterigma. Basidiospores often have an asymmetric shape due to the presence of a hilar appendage (apiculus) where the spore was attached to the sterigma.  Basidia line the gills of mushrooms, the pores of bracket fungi, and some surfaces of other fleshy fungi. In these fruiting bodies, the basidiospores are forcibly ejected from the basidium through an active mechanism that requires moisture. As a result they are found in the atmosphere during periods of high humidity, especially during late night or early morning hours. In contrast to this active discharge, basidiospores in puffballs, earthballs, bird's nest fungi, and stinkhorns are passively discharged by various methods. 

Asexual Reproduction in the Basidiomycota

Asexual spores are found in the basidiomycetes although they are not as common as in the ascomycetes. Conidium formation occurs in many species; in addition, specialized asexual spores occur in other basidiomycetes.