The Agaricomycotina is one of three major clades of Basidiomycota (the others are the Pucciniomycotina and Ustilaginomycotina). The Agaricomycotina contains roughly 20,000 described species, which is almost 70% of the (known) Basidiomycota. About 98% of the species of the Agaricomycotina are in a clade called the Agaricomycetes, which includes mushrooms, bracket fungi, puffballs, and others. The other major groups are the Tremellomycetes and Dacrymycetes. These latter groups include "jelly fungi" (Fig. 1), which have gelatinous, often translucent fruiting bodies (e.g., "witches butter" Tremella mesenterica), as well as many yeast-forming species (Hibbett 2007).

Figure 1. Phlogiotis (Tremiscus) helvelloides (Auriculariales).
© David S. Hibbett.

Members of the Agaricomycotina display the full range of ecological strategies that characterizes the Basidiomycota as a whole. To obtain carbon nutrition, Agaricomycotina decompose dead organic matter or enter into diverse associations (both antagonistic and benign) with plants, animals, and other fungi. Mycorrhizal associations with plants are present in many lineages of Agaricomycetes, including certain jelly fungi (Selosse et al. 2002). Mycoparasitism (parasitism of a fungus by a fungus) is especially widespread in the Tremellomycetes (Bandoni 1984). Few Agaricomycotina are medically important. An exception is Filobasidiella neoformans (also called Cryptococcus neoformans), which is a serious pathogen of immunocompromised individuals (Mitchell and Perfect 1995).

Agaricomycotina include the vast majority of edible mushrooms, most of which are in the Agaricomycetes. Several jelly fungi are cultivated for food in Asia, including the "wood ear" fungus, Auricularia auricula-judae (Fig. 2), and the white jelly fungus, Tremella fuciformis.

Figure 2. Cultivated fruiting bodies of Auricularia auricula-judae (Auriculariales).
© David S. Hibbett.