Marasmius oreades

Marasmius oreades
M. oreades the "Fairy Ring" mushroom.
Scientific classification
Kingdom:	Fungi
Division:	Basidiomycota
Class:	Agaricomycetes
Subclass:	Hymenomycetes
Order:	Agaricales
Family:	Marasmiaceae
Genus:	Marasmius
Species:	M. oreades
Binomial name
Marasmius oreades (Bolton) Fr (1836)

Marasmius oreades
Mycological characteristics
	gills on hymenium
	cap is convex or umbonate
	hymenium is adnate
	stipe is bare
	spore print is white
	ecology is saprotrophic
	edibility: choice

Marasmius oreades is also known as the scotch bonnet or fairy ring mushroom. The latter name tends to cause some confusion, as many other mushrooms grown in fairy rings (such as the edible Agaricus campestris, the poisonous Chlorophyllum molybdites, and many others).

Distribution and habitat

Marasmius oreades grows extensively throughout North America and Europe in the summer and fall, or year-round in warmer climates. It loves grassy areas such as lawns, meadows, and even dunes in coastal areas.

Description

It grows gregariously in troops, arcs, or rings (type II, which causes the grass to grow and become greener). The cap is 1-5 cm across; bell-shaped with a somewhat inrolled margin at first, becoming broadly convex with an even or uplifted margin, but often retaining a slight central bump; dry; smooth; pale tan or buff, occasionally white, or reddish tan; usually changing color markedly as it dries out; the margin sometimes faintly lined.^[1]

The bare, pallid stem grows up to about 7cm by 5mm in diameter.

The gills are attached to the stem or free from it,^[1] fairly distant (rather a distinctive character), and white or pale tan, dropping a white spore-print. The spores, themselves, are 7-10 x 4-6 µ; smooth; elliptical; inamyloid. Cystidia absent. Pileipellis without broom cells.^[1]

This mushroom can be mistaken for the toxic Clitocybe dealbata which lacks an umbo, is white to grey in color, and has closely spaced decurrent gills.

Edibility

A dried string of 50 fairy ring caps.

Many mushroom connoisseurs are fond of M. oreades^[1] and 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. The reason why this mushroom is so sweet-tasting is due to the presence of trehalose, a type of sugar that allows M. oreades to cheat death.^[2] When exposed to water after being completely dried out, the trehalose is digested as the cells completely revive, causing cellular reproduction and the creation of new spores to pick up again.

References

1. ^ ^{a b c d} Marasmius oreades (MushroomExpert.com)
2. ^ Marasmius oreades, the fairy ring mushroom, leprechaun. Tom Volk's Fungus of the Month for March 2003

External links

• Marasmius oreades in Index Fungorum.