Pleated Pluteus

Pluteus longistriatus

This small grayish-brown Pluteus can be recognized by the long striations that extend from the cap margin nearly to the center of the cap, revealing whitish flesh in the cracks.
Pleated Pluteus - Pluteus longistriatus Convex to slightly bell-shaped caps that were 2-3 cm in diameter. Caps were light brown and radially fibrillose. Free, white gills with short gills present. Stems were about 3-4 cm long. Pink spore print. 
https://www.jungledragon.com/image/72062/pleated_pluteus_-_pluteus_longistriatus.html Geotagged,Pleated Pluteus,Pluteus,Pluteus longistriatus,Summer,United States,fungus,mushroom

Appearance

Cap: 1-2 cm; convex at first, but becoming broadly convex or nearly flat; fragile; developing cracks and fissures that extend from the margin almost to the center; brownish gray

Gills: Free and close with short-gills frequent; whitish at first, but becoming pinkish with maturity

Stem: 3-5 cm long and 1-2 mm thick; bald or with fibrils; whitish

Spore Print: Pink
Pleated Pluteus - Pluteus longistriatus Convex to slightly bell-shaped caps that were 2-3 cm in diameter. Caps were light brown and radially fibrillose. Free, white gills with short gills present. Stems were about 3-4 cm long. Pink spore print.
https://www.jungledragon.com/image/58565/pleated_pluteus.html Geotagged,Pleated Pluteus,Pluteus longistriatus,Summer,United States,mushroom,pluteus

Distribution

Widely distributed in the United States from the Great Plains eastward, and occasionally reported in western North America.

Behavior

It's a very fragile mushroom and, in hot weather, its gills sometimes begin to dissolve, which can happen before the gills turn pink. This can cause misidentification.

Habitat

Saprobic on decaying hardwood logs and debris. It grows alone or gregariously during summer and fall.

References:

Some text fragments are auto parsed from Wikipedia.

http://eol.org/pages/6692637/overview
Taxonomy
KingdomFungi
DivisionBasidiomycota
ClassAgaricomycetes
OrderAgaricales
FamilyPluteaceae
GenusPluteus
SpeciesPluteus longistriatus