Fairy Ring Marasmius
Marasmius oreades
Type: gilled mushroom
Physical Characteristics
Convex to flat cap with a central bump (umbo), widely spaced gills that are free from the stem, and a very tough, pliable stem that does not snap easily.
Habitat & Growing Conditions
Grows primarily in grassy areas such as lawns, meadows, pastures, and parks, often forming distinct circles or arcs known as fairy rings.
Season & Fruiting Time
Typically found from late spring through autumn, often appearing several days after heavy rainfall.
Similar Looking Species
Marasmius wynneae (found in woodlands), Clitocybe dealbata (lacks the tough stem and has decurrent gills), and certain Galerina species (which have dark brown spore prints).
Ecological Role
Saprophytic, breaking down organic matter in the soil and grass thatch.
Fruiting Body
Cap is 1-5 cm across, tan to buff-colored, hygrophanous; Gills are distant, thick, and cream-colored; Stipe is 3-7 cm long, extremely tough and fibrous, colored similarly to or slightly darker than the cap.
Size
Cap diameter: 1-5 cm; Stipe: 2-7 cm long and 3-5 mm thick.
Spore Print
White
Distribution
Widespread across North America and Europe; found globally in temperate regions.
Identification Tips
The 'twist test' is a key identifier; the stem is so tough it can be twisted several times without snapping. Gills are unusually far apart and do not reach the stem.
Interesting Facts
This species can undergo 'anhydrobiosis,' meaning it can completely dry out in a drought and then revive and continue to drop spores once it rains again. The fairy rings they form are caused by the underground mycelium expanding outward in a circular pattern.
Safety reminder
AI mushroom identification is a best-effort estimate and can be wrong. Never use it to decide whether a mushroom is safe to handle or eat — always confirm with a qualified mycologist before any consumption.
Identified on: 4/24/2026
Mode: Standard