Ergot fruiting bodies. Coloured scanning electron micrograph (SEM) of the fruiting bodies of the fungus ergot (Claviceps purpurea). Fruiting bodies are the sexual reproductive structure of fungi. This fungus infects cereal crops and grasses, causing a reduced yield. During infection ergot induces the plants' cells to divide and enlarge, resulting in a large mass (black), called the sclerotium, which allows the fungus to survive adverse conditions. Ingestion of ergot causes poisoning (ergotism) in animals and humans, which can be fatal. Symptoms can include vomiting, gangrene and hallucinations. A number of medical drugs, as well as LSD, are derived from ergot.