Wild mushrooms fall into the plant category known as fungi. Within this category, some wild mushrooms are poisonous to humans. Poisonous mushrooms cause chemical injury either through touch or consumption.
Toxic wild mushrooms grow in a variety of places including forests, backyards and lawns. Approximately one percent of such mushrooms contain some type of toxin. Larry F. Grand of North Carolina State University Department of Plant Pathology says that it is best to avoid picking wild mushrooms, as there is currently no antidote for mushroom poisoning.
A small number of wild mushrooms are considered to be poisonous and contain any one of four deadly toxins, according to the Food and Drug Administration. The symptoms of toxic wild mushroom poisoning range from hallucinations and vomiting to organ failure and even death.
There is no definitive test to check wild mushrooms for toxins, which makes identification of such mushrooms near impossible. Many old wives’ tales, such as poisonous mushrooms being brown and ugly, have been proven untrue. Most toxic mushroom varieties, including the deadly "destroying angel," are white or consist of bright colors.