Mushroom, smut and rust are fungi which belong to class- Basidiomycetes of division-Basidiomycotina. Basidiomycetes is characterised with about sixteen thousand described species.
All these fungi of class- Basidiomycetes bear characteristic fruiting bodies called basidiocarps, which are most attractive and are often reffered as fungus flower. This class of fungi includes toadstools (toxic mushroom) puffballs, jelly fungi and shelf fungi and pathogen like smut and rust.