How to identify it?
Cap
Cap 1-5 cm across, convex, becoming flat, and often weakly umbonate; cream to pale yellow-brown or pinkish brown, darker at the center; surface smooth. Flesh thin, tough, white. Taste bitter.
Gills
Gills free to adnexed, white or pale tan, distant.

Scientific Classification

Phylum
Club fungi Class
Mushroom-forming fungi Order
Gilled fungi Family
Marasmiaceae Genus
Marasmius Species
Fairy ring mushroom