Unindentified Mushroom

I found these ones growing in large numbers on the ground and on top of dead wood.

Date: 05/30/2010
Location: Rockville, MD
Habitat: Growing in a cluster in the woods (near Woodmont Country Club)

Measurements
Stipe length - 81 mm
Stipe diameter at base: 7.5 mm wide, 4.5 mm thick
Stipe diameter at middle: 7.5 mm wide, 4.5 mm thick
Stipe diameter at apex: 7.5 mm wide, 4.5 mm thick
Pileus height: 17 mm
Pileus diameter: 37mm  x 27 mm

Description
Pileus - parabolic, round, light beige, dull, smooth, glabrous, unicolorous, margin is entire, plane.
Hymenium - gilled, adnate, gills are light brown, subdistant, soft, smooth, narrow
Stipe - central, equal, hollow, flexible, white, glabrous, compressed, inserted

Spore print - brown

Impressions
The most striking characteristic of this specimen was the was the equal and compressed white stipe. I have no idea what it could be and therefore will submit it to Mushroom Observer to get some ideas and will post the result of the discussion here later.

Mushroom Observer Comments
Dave W and Douglas Smith suggested that this could be a Psathyrella, most probably Psathyrella candolleana. According to Michael Kuo's Mushroom Expert, this mushroom is very variable in color and in habitat and it is very difficult to identify Psathyrellas without microscopic analysis. Therefore it may be safer to call this one just Psathyrella sp. Most probably I should type it by sequencing but the mushroom has already deteriorated (it almost disappeared after leaving it outside of the fridge over night).