Claviceps purpurea (Fr.) Tul., Ergot Fungus, PLP847_2018_127
C. purpurea is a parasite of grasses in the subfamily Pooidae, and was found on Elymus repens in East Lansing, MI. C. purpurea produces dark purple to brown sclerotia which grow in infected ovarian tissue of the host grass. The fungus infects through the stigma and begins growing in the ovary after 3 days. Eventually, the entire ovary is replaced by fungal tissue (Shaw and Mantle 1980). Pažoutová et al. 2015 determined that C. purpurea can be divided into four species based on gene flow and a multigene phylogeny, including C. purpurea sensu stricto, C. humidiphila, C. spartinae, and C. arundinis. In the United States, all sclerotia found on Elymus repens were in C. purpurea sensu stricto. The ITS1F-LR3 contig confirms this grouping for isolate PLP847_2018_127.
Other names for this species have included Sphaeria purpurea Fr. (1823), Cordyceps purpurea (Fr.) Fr. (1849), and Pseudocenangium purpureum (Fr.) A. Knapp. The fungus is known for its production of ergot alkaloids (Flieger et al. 1997), many of which are quite toxic but pharmaceutically useful (ergotamines, ergoxines, ergotoxines, ergoannines). There is even a popular hypothesis, maybe unlikely, that contamination of grain with C. purpurea in Salem was involved in the town’s infamous witch trials (Woolf 2000).
Figure 1. A) The sclerotia appeared dark brown, about 10 mm in length, growing in one to several sclerotia per spike on Elymus repens. B) The habitat was a grassy margin under Juglans nigra, outside of Baker Woodlot. C) Cut sclerotia, revealing the purple surface and white interior. D) The cells inside the sclerotia appear cuboid and to contain lipid vesicles (1000X).
Flieger M, Wurst M, Shelby R. Ergot alkaloids—sources, structures and analytical methods. Folia microbiologica. 1997 Feb 1;42(1):3-0.
Pažoutová S, Pešicová K, Chudíčková M, Šrůtka P, Kolařík M. Delimitation of cryptic species inside Claviceps purpurea. Fungal Biology. 2015 Jan 1;119(1):7-26.
Shaw BI, Mantle PG. Host infection by Claviceps purpurea. Transactions of the British Mycological Society. 1980 Jan 1;75(1):77-90.
Woolf A. Witchcraft or mycotoxin? The Salem witch trials. Journal of Toxicology: Clinical Toxicology. 2000 Jan 1;38(4):457-60.09.23.18