When gathering morels, care must be taken to distinguish them from the poisonous false morels, including Gyromitra esculenta, Verpa bohemica, and others. Although the false morels are sometimes eaten without ill effect, they can cause severe gastrointestinal upset and loss of muscular coordination (including cardiac muscle) if eaten in large quantities or over several days in a row. They contain a gyromitrin-like toxin (an organic, carcinogenic poison) that is produced by the mushroom.
The false morels can be told apart from the true morels by careful study of the cap, which is often “wrinkled” or “brainy”, rather than honeycomb or net-like. Gyromitra esculenta has a cap that is generally darker and larger than the true morels (Morchella sp.). The caps of early morels (Verpa sp.) are attached only at apex (top) of cap, unlike true morels which have caps that are attached at or near the bottom
