Gyromitra

Gyromitra is a genus of ascomycete fungi in the family Helvellaceae, commonly known as false morels. The genus comprises several dozen species distributed across temperate regions of Europe, Asia, and North America. They typically produce fruiting bodies in spring, appearing in woodlands, clearings, and forest edges, often near conifers and hardwoods.

Morphologically, Gyromitra fruit bodies have irregular, wrinkled caps that resemble a brain or saddle in shape, with colors ranging from reddish-brown to tan. The cap is usually attached to the stem at or near the apex, and the interior can be hollow or loosely filled depending on the species. In contrast to true morels (Morchella), Gyromitra caps generally lack the distinct honeycomb pattern and may appear more lobed or convoluted.

All Gyromitra species contain gyromitrin, a toxin that hydrolyzes to monomethylhydrazine (MMH). MMH is a potent irritant and neurotoxin, and exposure can cause nausea, vomiting, dizziness, abdominal pain, confusion, seizures, and in severe cases coma or death. Toxicity varies among species and with preparation, but there is no safe, reliable method to render these fungi edible in all circumstances. As a precaution, many authorities advise against consuming Gyromitra altogether.

Notable species include Gyromitra esculenta, the common false morel, widespread in Europe, Asia, and North America. Other species such as Gyromitra caroliniana occur in North America, and Gyromitra infula in parts of Europe and Asia. Taxonomic placement and species boundaries continue to be refined as mycological classifications evolve.