(2010) May Mushroom of the Month...
Gyromitra esculenta, the beefsteak morel
Commonly known as the beefsteak morel, false morel, brain mushroom, lorchel, and red caps, Gyromitra esculenta causes more consternation among mushroom hunters who eat this species than any other mushroom. The beefsteak morel is poisonous! It is very hard to distinguish from other members of the genus Gyromitra (G. fastigiata aka G. brunnea,, G. gigas aka G. korfii, G. infula) almost all of which are also poisonous. The poison in G. esculenta is cumulative, i.e., people can eat it for years then pass a threshold and become very ill. In Europe, at least, deaths have occurred. Symptoms of Gyromitra poisoning are primarily gastroenterological (nausea, vomiting, bloody diarrhea and muscle cramps). In older field guides the genus Gyromitra was part of the genus Helvella.
The cap of the beefsteak morel is reddish brown and very wrinkled and folded hence the name the brain mushroom. The cap is 1 1/2 to 4 inches wide, 1 ½ to 3 ½ inches tall and the stalk is 1 to 4 inches tall and ½ to 2 inches wide. Cut in two, the cap interior has many chambers. The stalk is hollow, usually singly-chambered but occasional ly it has multiple chambers.
The poison in G. esculenta is gyromitrin which converts to monomethylhydazine after digestion. Monomethylhydrazine is a rocket fuel and hence is very volatile which has led people to boil the mushroom several times discarding the cooking water in an attempt to get rid of the poison. Cooks boiling the mushroom or drying it have been sickened by the vapors given off by the mushrooms. To add insult to injury monomethylhydrazine is not only poisonous, it is also a carcinogen known to cause cancer in animals.
G. esculenta occurs singly, scattered, and in small groups in both hardwoods and conifers. It is an early spring mushroom that fruits at the same time as the desirable morels and is often found by morel pickers.
Charles McIlvaine, a mycologist noted for his penchant to eat almost anything and to enjoy mushrooms described by most other mycologist as insipid or worse, said “It is not probable that in our great food-giving country anyone will be narrowed to G. esculenta for a meal. Until such an emergency arrives, the species would be better left alone.”