Marasmius oreades, also known as the fairy ring mushroom or fairy ring champignon, is a mushroom native to North America and Europe. Its common names can cause some confusion, as many other mushrooms grow in fairy rings, such as the edible Agaricus campestris and the poisonous Chlorophyllum molybdites.
|gills on hymenium|
|cap is convex or umbonate|
|hymenium is adnate|
|stipe is bare|
|spore print is white|
|ecology is saprotrophic|
Distribution and habitatEdit
Marasmius oreades grows extensively throughout North America, especially the east where they are also more diverse, and Europe in the summer and autumn (fall) (June–November in the UK), or year-round in warmer climates. It appears in grassy areas such as lawns, meadows, and even dunes in coastal areas.
Marasmius oreades grows gregariously in troops, arcs, or rings (type II, which causes the grass to grow and become greener). The cap is 1–5 centimetres (1⁄2–2 inches) across; bell-shaped with a somewhat inrolled margin at first, becoming broadly convex with an even or uplifted margin, but usually retaining a slight central bump- an "umbo"; dry; smooth; pale tan or buff, occasionally white, or reddish tan; usually changing color markedly as it dries out; the margin sometimes faintly lined.
The gills are attached to the stem or free from it, fairly thick and spaced apart, and white or pale tan, with a cyanide-like odor and dropping a white spore print. The spores measure 7–10 μm × 4–6 μm; they are smooth, elliptical, and inamyloid. Cystidia absent. Pileipellis without broom cells.
Marasmius oreades is a choice edible mushroom. Its sweet taste lends it to baked goods such as cookies. It is also used in foods such as soups, stews, etc. Traditionally, the stems (which tend to be fibrous and unappetizing) are cut off and the caps are threaded and dried in strings. A possible reason why this mushroom is so sweet-tasting is due to the presence of trehalose, a type of sugar that allows M. oreades to resist death by desiccation. When exposed to water after being completely dried out, the trehalose is digested as the cells completely revive, causing cellular processes, including the creation of new spores, to begin again.
- Trudell, Steve; Ammirati, Joe (2009). Mushrooms of the Pacific Northwest. Timber Press Field Guides. Portland, OR: Timber Press. pp. 113–114. ISBN 978-0-88192-935-5.
- Marasmius oreades (MushroomExpert.com)
- Davis, R. Michael; Sommer, Robert; Menge, John A. (2012). Field Guide to Mushrooms of Western North America. Berkeley: University of California Press. pp. 27, 188–189. ISBN 978-0-520-95360-4. OCLC 797915861.
- Miller Jr., Orson K.; Miller, Hope H. (2006). North American Mushrooms: A Field Guide to Edible and Inedible Fungi. Guilford, CN: FalconGuide. p. 196. ISBN 978-0-7627-3109-1.
- Marasmius oreades, the fairy ring mushroom, leprechaun. Tom Volk's Fungus of the Month for March 2003
- Elekes, Carmen Cristina; Busuioc, Gabriela. "The Mycoremediation of Metals Polluted Soils Using Wild Growing Species of Mushrooms". Engineering Education.
Media related to Marasmius oreades at Wikimedia Commons