Gyromitra esculenta

Gyromitra esculenta: The Brain-Shaped Mushroom with a Deadly Secret

Imagine a mushroom that looks like a brain, grows in sandy soils under coniferous trees, and can be deadly if eaten raw. This is the fascinating yet dangerous Gyromitra esculenta, also known as the false morel.

The Appearance of Gyromitra esculenta

With its brain-shaped cap up to 10 cm high and 15 cm wide, this fungus stands out in the forest. The stipe is stout and white, attached at several points, making it a unique sight among other mushrooms. Its color can vary from reddish-brown to dark brown or even golden, often darkening with age. But don’t be fooled by its appearance; this mushroom harbors a deadly secret.

The Danger of Gyromitra esculenta

While Gyromitra esculenta is commonly consumed when parboiled, it can still contain toxic compounds like gyromitrin and monomethylhydrazine. These toxins can cause severe poisoning with symptoms including vomiting, diarrhea, dizziness, lethargy, headaches, delirium, and even coma after 5-7 days. The mushroom was first described as Helvella esculenta in 1800 but is now classified under the genus Gyromitra.

Geographical Distribution and Hunting Period

G. esculenta can be found across North America, Central Europe, and other parts of Turkey. It grows on sandy soil in temperate coniferous forests and deciduous woodlands, particularly under pines and aspen trees. The hunting period is from April to July, with the mushroom being abundant or rare depending on the location.

The Toxicity of Gyromitra esculenta

Gyromitrin, a poison found in varying levels among populations, can be lethal at doses of 10-30 mg/kg for children and 20-50 mg/kg for adults. Children are more severely affected by the toxin, but it is unclear why this is the case. The toxicity appears to vary geographically, with higher altitudes having lower concentrations of toxin.

How Gyromitrin Affects the Body

Gyromitrin reacts with pyridoxal-5-phosphate to form a hydrazone, which reduces production of the neurotransmitter GABA and leads to neurological symptoms. The toxin also causes oxidative stress, elevates histamine levels, and inhibits diamine oxidase, leading to headaches, nausea, vomiting, abdominal pain, and liver necrosis.

Preparation and Consumption

The mushroom is marketed and consumed in several countries, including Europe and North America. In Finland, it is highly regarded and sold with warning labels and instructions for preparation. However, cooking the fungus can produce hydrazine fumes that can cause poisoning if not handled properly.

Controversies Surrounding Gyromitra esculenta

There are controversies surrounding the consumption of Gyromitra esculenta, with some experts criticizing chefs for including it in recipes without proper knowledge of its toxicity. After 5 rounds, this content is reduced to 7%. The gyromitrin is leached into the water where it will remain, therefore the parboiling water must be discarded and replaced with fresh water after each round of boiling.

Conclusion

Gyromitra esculenta, a fascinating yet dangerous mushroom, continues to intrigue us. Despite its deadly secret, it is still consumed in certain regions, highlighting the complex relationship between humans and nature. Always approach this mushroom with caution and follow proper preparation methods to avoid the potentially fatal consequences of consuming it raw or improperly prepared.