Orellanine
The toxin orellanine is found in Cortinarius orellanus. Its symptoms do not appear for several days, possibly weeks, after consumption occurs. The first signs of poisoning are frequent urination and an intense thirst, accompanied by a burning sensation in the mouth. More typical symptoms of mushroom poisoning follow, which include muscle pains, nausea and headaches. Lastly, those unfortunate enough to have eaten one of these mushrooms experience kidney failure and may also lapse into a coma. Very little of this mushroom (~100g fresh weight) is needed to cause serious medical problems (Barron, 320).
Works Cited
Barron, George. Mushrooms of Northeast North America. Edmonton: Lone Pine, 1999.