False Morel

Appearance

Resembling a brain, the irregularly shaped cap may be up to 10 centimetres high and 15 centimetres wide. Initially smooth, it becomes progressively more wrinkled as it grows and ages. The cap colour may be various shades of reddish-, chestnut-, purplish-, bay-, dark or sometimes golden-brown. Specimens from California may have more reddish-brown caps. Attached to the cap at several points, the stipe is 3–6 centimetres high and 2–3 centimetres wide. "Gyromitra esculenta" has a solid stipe whereas those of true morels are hollow. The smell can be pleasant and has been described as fruity, and the fungus is mild-tasting. The spore print is whitish, with transparent spores that are elliptical and 17–22 μm in length.

"Gyromitra esculenta" resembles the various species of true morel, although the latter are more symmetric and look more like pitted gray, tan, or brown sponges. Its cap is generally darker and larger.

Naming

The fungus was first described in 1800, by mycologist Christian Hendrik Persoon, as "Helvella esculenta", and gained its current accepted binomial name when the Swedish mycologist Elias Magnus Fries placed it in the genus "Gyromitra" in 1849. The genus name is derived from the Greek terms "gyros"/γυρος "round" and "mitra"/μιτρα "headband". Its specific epithet is derived from the Latin "esculentus", "edible".

It is known by a variety of common descriptive names such as "brain mushroom," "turban fungus," "elephant ears", or "beefsteak mushroom/morel," although "beefsteak mushroom" can also refer to the much less toxic basidiomycete "Fistulina hepatica". Dating from the 19th century, the German term "lorchel" is a result of the older "lorche", itself from the 18th century Low German "Lorken", aligning with the similar-sounding "morchel".

"Gyromitra esculenta" is a member of a group of fungi known as "false morels", so named for their resemblance to the highly regarded true morels of the genus "Morchella". The grouping includes other species of the genus "Gyromitra", such as "G. infula", "G. caroliniana" and "G. gigas". While some of these species contain little to no gyromitrin, many guidebooks recommend treating them all as poisonous, since their similar appearance and significant intraspecific variation can make reliable identification difficult.

The more distantly related ascomycete mushrooms of the genus "Verpa", such as "V. bohemica" and "V. conica", are also known as false morels, early morels or thimble morels; like the "Gyromitra", they are eaten by some and considered poisonous by others.

The genus "Gyromitra" had been classically considered part of the family Helvellaceae, along with the similar-looking elfin saddles of the genus "Helvella". Analysis of the ribosomal DNA of many of the Pezizales showed "Gyromitra esculenta" and the other false morels to be only distantly related to the other members of the Helvellaceae and instead most closely related to the genus "Discina", forming a clade which also contains "Pseudorhizina" and "Hydnotrya". Thus the four genera are now included in the family Discinaceae.

Distribution

"Gyromitra esculenta" grows on sandy soil in Temperate coniferous forest and occasionally in deciduous woodlands. Among conifers it is mostly found under pines, but also sometimes under aspen. The hunting period is from April to July, earlier than for other species, and the fungus may even sprout up with the melting snow. It can be abundant in some years and rare in others. The mushroom is more commonly found in places where ground has been disturbed, such as openings, rivulets, washes, timber clearings, plowed openings, forest fire clearings, and roadsides. Enthusiasts in Finland have been reported burying newspaper inoculated with the fungus in the ground in autumn and returning the following spring to collect mushrooms.

Although more abundant in montane and northern coniferous woodlands such as the Sierra Nevada and the Cascade Range in northwestern North America, "Gyromitra esculenta" is found widely across the continent, as far south as Mexico. It is also common in Central Europe, less abundant in the east, and more in montane areas than lowlands. It has been recorded from Northern Ireland, from Uşak Province in Western Turkey, and from the vicinity of Kaş in the Antalya Province of Turkey's southern coast.

Habitat

"Gyromitra esculenta" grows on sandy soil in Temperate coniferous forest and occasionally in deciduous woodlands. Among conifers it is mostly found under pines, but also sometimes under aspen. The hunting period is from April to July, earlier than for other species, and the fungus may even sprout up with the melting snow. It can be abundant in some years and rare in others. The mushroom is more commonly found in places where ground has been disturbed, such as openings, rivulets, washes, timber clearings, plowed openings, forest fire clearings, and roadsides. Enthusiasts in Finland have been reported burying newspaper inoculated with the fungus in the ground in autumn and returning the following spring to collect mushrooms.

Although more abundant in montane and northern coniferous woodlands such as the Sierra Nevada and the Cascade Range in northwestern North America, "Gyromitra esculenta" is found widely across the continent, as far south as Mexico. It is also common in Central Europe, less abundant in the east, and more in montane areas than lowlands. It has been recorded from Northern Ireland, from Uşak Province in Western Turkey, and from the vicinity of Kaş in the Antalya Province of Turkey's southern coast.

Defense

Toxic reactions have been known for at least a hundred years. Experts speculated the reaction was more of an allergic one specific to the consumer, or a misidentification, rather than innate toxicity of the fungus, due to the wide range in effects seen. Some would suffer severely or perish while others exhibited no symptoms after eating similar amounts of mushrooms from the same dish. Yet others would be poisoned after eating "Gyromitra esculenta" for many years without ill-effects. However, the fungus is now widely recognized as potentially deadly.

"Gyromitra esculenta" contains levels of the poison gyromitrin that vary locally among populations; although these mushrooms are only rarely involved in poisonings in either North America or western Europe, intoxications are seen frequently in eastern Europe and Scandinavia. A 1971 Polish study reported at the time that the species accounted for up to 23% of mushroom fatalities each year. Death rates have dropped since the mid-twentieth century; in Sweden poisoning is common, though life-threatening poisonings have not been detected and there was no fatality reported over the 50 years from 1952 to 2002. "Gyromitra" poisonings are rare in Spain, due to the widespread practice of drying the mushrooms before preparation and consumption, but has a mortality rate of about 25%.

A lethal dose of gyromitrin has been estimated to be 10–30 mg/kg for children and 20–50 mg/kg in adults. These doses correspond to around 0.2–0.6 kilograms and 0.4–1 kilogram of fresh mushroom respectively. However, individual responses may vary and people who have ingested similar amounts may develop anything from minimal to severe toxicity. Evidence suggests that children are more severely affected; it is unclear whether this is due to a larger weight consumed per body mass ratio or to differences in enzyme and metabolic activity. Although the amount of gyromitrin present can be significantly reduced through parboiling, there is evidence that repeated consumption can increase risk of toxicity.

Cultural

Although potentially fatal if eaten raw, "Gyromitra esculenta" is a popular delicacy in Scandinavia, Eastern Europe, and the upper Great Lakes region of North America. Although popular in some districts of the eastern Pyrenees, it is prohibited from sale to the public in Spain. It may be sold fresh in Finland, but it must be accompanied by warnings and instructions on correct preparation.

Although it is still commonly parboiled before preparation, evidence suggests that even this procedure may not make "Gyromitra esculenta" entirely safe for consumption. When consumed, the principal active agent, gyromitrin, is hydrolyzed into the toxic compound monomethylhydrazine. The toxin affects the liver, central nervous system, and sometimes the kidneys. Symptoms of poisoning involve vomiting and diarrhea several hours after consumption, followed by dizziness, lethargy and headache. Severe cases may lead to delirium, coma and death after five to seven days.