Gyromitra esculenta (false morel) and edible species, Morchella esculenta (morel, sponge mushroom, or honeycomb mushroom) and Morchella elata (black morel)

The toxic Gyromitra esculenta ("false morel", panel A) is often mistaken for the edible mushrooms, Morchella esculenta ("morel", panel B) and Morchella elata ("black morel", panel C) leading to delayed onset seizures, gastroenteritis, renal, and liver toxicity caused by the toxin, gyromitra which is metabolized to monomethylhydrazine after ingestion. Gyromitra esculenta mushrooms are found in North America and parts of Europe. Gyromitra mushrooms may be eaten if parboiled. In parboiling the mushroom is boiled and the water discarded before further preparation. Some evidence suggests that even parboiling does not render the Gyromitra completely safe.