A sooty ear of wheat

This ear of wheat is affected by a harmless sooty head mould, caused by a variety of different fungi.

In the past infection of cereals by another species of fungus was a serious cause of ill-health. Ergotism is the effect of long term ergot poisoning by the ingestion of the alkaloids produced by the fungus Claviceps purpurea  that infects rye and other cereals. It is also known as ergotoxicosis, ergot poisoning and Saint Anthony's Fire. Symptoms include painful seizures, diarrhoea, itching, mania or psychosis, headaches, nausea and vomiting and a dry gangrene which leads to the death of affected tissues. The convulsive symptoms that can be a result of consuming ergot-tainted rye are said by some to be the cause of accusations of bewitchment that led to the Salem witch trials.