Verpa bohemica, the wrinkled thimble cap, and to some extent Verpa conica, the smooth thimble cap, bear some resemblance to the half-free morel. They are easily distinguished by:
- The folds on the cap instead of the ridges and pits seen in true morels
- The cap of the Verpa attaching (“perching”) to the top of the stipe. In contrast, the half-free morel cap attaches to the stipe, half way up the cap, leaving half of the cap hanging free like a skirt.
- The stipe of Verpa spp. containing a cotton-like tissue. All true morels have a hollow stipe.
|Verpa bohemica||Verpa conica|
Verpa bohemica can more likely be confused with Morchella punctipes than the smooth capped Verpa conica.
Verpa spp. are considered slightly poisonous and are not authorized for collecting and selling in Michigan.
|Verpa: Cap “perched” atop the stipe filled with cottony tissue||M. punctipes: Cap attached halfway down the hollow stipe|
There are several species of Gyromitra found in Michigan which fruit at the same time as morels.
Chemical analysis has shown Gyromitra species contain the chemical Gyromitrin as well as other toxins, including an unidentified carcinogen, which remain in the mushrooms and can build up over time (bioaccumulate) in the human body with repeated Gyromitra meals.
Our digestive system converts Gyromitrin into Monomethylhydrazine; a volatile toxin and carcinogen. Commonly referred to as “rocket fuel”, it is used as a propellant in rocket engines.
The amount of Gyromitrin varies in species and individual but the effects can be so devastating, this mushroom should never be consumed. Research is ongoing to understand this toxic component of Gyromitra species.
Gyromitra esculenta, the false morel or the beef-steak morel, also fruits at the same time as morels. This mushroom has been responsible for many deaths in Europe and several poisonings in the U.S. G. esculenta is distinguished from Morchella species by its folded, brain-like cap and association with conifers. Morchella spp. are usually found in association with hardwoods.
Gyromitra brunnea, known as the “Gabled False Morel”, is found in or near hardwood forests and its lobe-like cap can appear pinched with seams.
Gyromitra korfii, regarded as the “bull-nose False Morel”, is also found in or near hardwood forests, especially near stumps or dying trees. Its wavy cap folds over the stipe with little overhang; it can appear block and stemless.
Compare the multi-chambered stipe of the Gyromitra brunnea (left) to the “fluted chambered” stipe of the Morchella exuberans (right).
Bueg, M., Bessette, A, Bessette, Arlene. 2014. Ascomycete Fungi of North America: a mushroom reference guide.University of Texas Press. 488p.
Kuo M. 2005. Morels. Ann Arbor: Univ. Michigan Press. 205p.
Kuo, M., Dewsbury, D.R., O’Donnell, K., Carter, M.C.,Rehner, S.A., Moore, J.D., Monclavo, J.M., Canfield, S.A., Stephenson, S. L., Methven, A.S., Volk, T.J. 2012. Taxonomic revision of the true morels (Morchella) in Canada and the United States. Mycologia 104(5):1156-1177, doi:10.3852/11-375.
Kuo, M., Metheven, A. 2014. Mushrooms of the Midwest. University of Illinois Press. Urbana, Chicago, and Springfield.
Rodgers, R. The Fungal Pharmacy. 2011. North Atlantic Books, Berkeley, CA. pp. 287-291.
Shavit, Elinor and Efrat. 2010. Lead and arsenic in Morchella esculenta fruitbodies collected in lead arsenate contaminated apple orchards in northeastern United States: A preliminary study. Fungi3(2):11-18.
Michael W. Beug. Poisonous and hallucinogenic mushrooms.
Kuo, M. (2012, November) The Morchellaceae: True morels and verpas.