brain mushroom

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A fungus common in Europe and North America and one of several species of fungi known as false morels, Gyromitra esculenta.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a poisonous gyromitra; the surface of the fertile body is smooth at first and becomes progressively undulating and wrinkled (but never truly pitted); color varies from dull yellow to brown