Common stump brittlestem

The cap of Psathyrella piluliformis is 2-4cm across and initially hemispherical, becoming bell-shaped and eventually almost flat. White veil fragments adhere to and overhang the rim, they get smaller as the fruitbody ages, eventually becoming blackened by spores. The fragile caps crowd together in clumps, some of the caps getting broken as others expand beside them. Initially caps are dark red-brown, fading through date-brown to yellow-brown. Mature specimens are noticeably hygrophanous meaning they change colour depending on whether the surface is moist or dry, becoming pale tan or beige from the edge of the cap in dry weather. The narrow gills of Psathyrella piluliformis are adnate and quite closely spaced. Initially pinkish beige, they gradually turn dark brown and eventually almost black. The gills of this mushroom are very brittle. Stems are typically 4 to 8 mm in diameter and grow to 8 cm long, straight or slightly curved and often lined with silky fibres. The partial veil that covers the young gills soon tears as the cap expands, leaving white fragments attached to the cap rim and little or no evidence on the stem, which has a matt, floury surface near the apex and is much smoother towards the base. As the fruit bodies mature, falling spores darken the stems, most noticeably towards the base.