According to Wikipedia, lists of really important individuals are reported to have died from wild mushrooms poisoning and also have made history for the need to perform comprehensive research to prevent further deaths. It's feared that most of these deaths and serious illnesses resulted due to confusion and mis-identification on species that appear to have same characteristics. The morel (Morchella) Navigate here for more; recent post by Thedailyworld, example, is edible and very tasty. However certain species are incredibly dangerous (false morels) and if confused with the edible ones and also consumed in great quantities can lead to severe gastrointestinal distress.  
Most cases of serious discomforts as well as deaths have resulted as a result of values in standard myths about wild mushrooms. In general, traditional identification method should not be applied to spot species in locations that are different. Most values are proven wrong and are misleading. Belief that many dangerous species are bright colored is not backed by the facts. It is known that the lethal galerina is brownish in color. The death cap is generally liked by insects and animals and consequently overruling the standard belief that if insects consume, then humans can eat. It doesn't matter the form of the untamed fungi for it being poisonous or edible. Many beliefs ensure it is that the nontoxic ones are rounded or flat while the dangerous are pointed in shape. For example an older death cap is round in shape. The death cup as well as the genus species enjoy a fungal toxin which doesn't break very easily just by cooking or warming up. Therefore, it is not safe to state that if all mushrooms are cooked nicely they are not poisonous. Lethal Amanitas tastes excellent but regular beliefs have it that dangerous species taste awful. It is also not true the poisonous species darken silver. The best advice is, do not eat it, in case you're not sure of its safe nature.  
Learning all about the edible species and ability to distinguish poisonous ones especially in cases where characteristics appear the same is the ideal practice. Some wild mushrooms are seen harvesting together with a single species nontoxic while the other poisonous but looking the exact same. This can be quite mystifying and requires careful identification. Comprehensive researches & activities in hunting must be applied and one must seldom use traditional techniques to figure out things. The online information has rather a major library particularly of photos, write-ups and videos on how you can quickly discover inedible and edible species.  
Most victims will have gastrointestinal discomforts, which may result in vomiting, and diarrhea. In some severe cases, organ failure might occur because of very high levels of toxins in the body. In most cases, victims have been hospitalized and in serious cases lost their lives. In some areas where these untamed species have sprouted, they are made poisonous by contamination with pesticides sprayed on other toxins and the surfaces. It is advisable not to consume them whenever you see them growing in such type of areas. Species with coprine toxic compounds are harmless although the second one takes alcohol the result begin showing up alike the hang over signs. It is advisable to make the wild mushrooms properly, while searching for them, wash the hands of yours totally and stay away from mixing them in a basket.