The category basidiomycete includes mushrooms, puffballs, polypores, jellyfungi, and rust. These fungi sexually reproduce producing spores on a basidium. A basidium is a small club shaped structure typically bearing 4 basidiospores at the tips of minute projections. The basidium is unique to basidiomycetes which distinguishes them from other fungi. The picture above is of some mushrooms with basidiums.