THE USTILAGINALES (SMUT FUNGI) OF OHIO*

The smut fungi are in the order Ustilaginales with one family, the Ustilaginaceae, recognized. They are all plant parasites. In recent monographs 276 species in 22 genera are reported in North America and more than 1000 species have been reported from the world (Fischer, 1953; Zundel, 1953; Fischer and Holton, 1957). More than one half of the known smut fungi are pathogens of species in the Gramineae. Most of the smut fungi are recognized by the black or brown spore masses or sori forming in the inflorescences, the leaves, or the stems of their hosts. The sori may involve the entire inflorescence as Ustilago nuda on Hordeum vulgare (fig. 2) and U. residua on Danthonia spicata (fig. 7). Tilletia foetida, the cause of bunt of wheat in Ohio, sporulates in the ovularies only and Ustilago violacea which has been found in Ohio on Silene sp. forms spores only in the anthers of its host. The sori of Schizonella melanogramma on Carex (fig. 5) and of Urocystis anemones on Hepatica (fig. 4) are found in leaves. Ustilago striiformis (fig. 6