Ergot is a fungus that grows on Rye and Heather.
In 944 A.D. in Paris, France, the average population would consume rye bread daily for food. A particular incident in which the rye bread started to go bad, and the population did not notice. People were buying and serving rye bread infected with the ergot fungus. On a particular night in mid 944 A.D. people in Paris were enjoying dinner and drinking lightly. Around two hours later, people were in the streets considered to be mad. Half of the population of Paris died over the course of a few days of absolute insanity. This incident is referred to as the Ergot epidemic; the term "Werewolf" derives from people who had ingested ergot infected bread.
Consumption of the ergot fungus right off of the rye stalk is an absolutely terrible idea. This will cause Ergotism and you will suffer the same fate as the many people in Paris. No one should consume this fungus, as it will most definitely kill you.