Tilletia walkeri, a new species on Lolium multiflorum and L-perenne

Tilletia walkeri (Ustilaginales: Tilletiaceae) is described as a new specie s of partial bunt infecting Lolium multiforum, annual ryegrass, and L. pere nne, perennial ryegrass in the United States and Australia, respectively. T he new species is characterized by large, tuberculate teliospores with the exospore ornamentation comprised of incompletely cerebriform ridges in surf ace view. Teliospores of T walkeri are compared with those of T indica and other similar species of Tilletia, and the issue of Neovossia versus Tillet ia is discussed. A key is provided to smuts known to occur on species of Lo lium.