Mankind has known about Claviceps purpurea for a long time, and its appearance has been linked to extremely cold winters that were followed by rainy summers.
The sclerotial stage of C. purpurea conspicuous on the heads of ryes and other such grains is known as ergot. Favorable temperatures for growth are in the range of 18-30 °C. Temperatures above 37 °C cause rapid germination of conidia. Sunlight has a chromogenic effect on the mycelium, with intense coloration. Cereal mashes and sprouted rye are suitable substrates for growth of the fungus in the laboratory.
Read more about this topic: Ergot