2. club fungi
explanation:
Corn smut is caused by Ustilago maydis while wheat rust is caused by Puccinia triticina. Both Ustilago maydis and Puccinia triticina are classified under division Basidiomycota. Basidiomycota is also called as club fungi. These fungi form specific club-shaped fruiting bodies called basidia. Basidia are the site for the formation of basidiospores.
