Ergotism, or ergot poisoning, is a condition caused by continued ingestion of feed containing ergot. The fungus is found growing on barley, wheat, and other grasses. Bluegrass, brame, and fescues have been suspected of being infected. Claviceps purpurea is the fungus most often involved, but probably other fungi produce ergot. The sclerotium (compact mass of hardened mycelium) of the parasitic fungus replaces the seed or grain.
Stocker, E. Dean
"A Case of Ergotism in the Bovine,"
Iowa State University Veterinarian: Vol. 21
, Article 10.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol21/iss3/10