Smut

Smut, any of more than 700 species of parasitic fungi that attack flowering plants and cause serious economic loss, especially to the cereal grasses. The various smut diseases are characterized by masses of sooty spores that grow from the plant in bodies called sori during the fungus's last stage of growth. Many smuts begin growth in the plant embryo and feed on maturing plant tissue through a network of filaments, or hyphae. When the fungus is ready to reproduce, an often blisterlike sorus appears and then breaks open, and the black, powdery fungus spores are borne away by winds.

Among smuts that stunt or destroy grains is the common corn smut, Ustilago maydis, which forms gray-black tumors on or near the ears. Loose smut, U. tritici, and stinking smut, Tilletia foetida (called bunt), attack wheat, the latter permeating healthy grain with a fishy odor.