Ustilaginomycotina comprises 115 genera with more than 1700 species. The subphyla is mostly plant parasites on vascular plants, and the distribution of the subphyla is therefore restricted to the distribution of the host. The group is also called the true smutfungi because of the production of teliospores. The name smut is still used as a term since it circumscribes the organization and life cycle of Ustilaginomycotina, but it is not a taxonomic term. Ustilaginomycotina has some of the best known and studied genera of plant parasites like Ustilago and Tilletia and it is also of great economic importance.