The image here represents the Agaricus augustus from the Basidiomycota family (See links page). The Basidiomycetes are a large and diverse group and include forms currently known as mushrooms, puffballs, shelf fungi and rust fungi. In general, Basidiomycota are typically mycelial with a complex dolipore septum and sometimes with clamp connections. Some species grow as yeast. Sexual reproduction is by fusion of compatible hyphae leading to production of basidiospores on basidia. May form a fruit body (basidiocarp, eg. toadstool). Asexual reproduction is rare, but usually by conidia. 

Evidence from molecular studies show that there are three lineages in the Basidiomycota, that diverged early in their history (Basidiomycota split from Ascomycota roughly 500 million years ago). The Uredinomycetes, or rust fungi, are shown to be the most advanced out of the three. They contain some of the most important pathogens of crop plants (for example, Puccinia graminis on wheat). The Ustilaginomycetes, or smut fungi, are another important group of pathogens. The final group, the Hymenomycetes, consists of two subgroups, the Tremellales, and all the other groups (including Agaricales and Gasteromycetes). It is worth saying that the clamp connection at the septa that is found in at least some members of all three groups may be a primitive character of the phylum that evolved before the first basidiomycete radiation.