The cap is initially dark-brown, convex or bell-shaped, becoming paler and umbonate as it matures.  The common name comes from the spore-shape, whch is irregular and knobbly.  The striate stem is characteristic.

Other species of Entoloma

microscope

Identification is very difficult, requiring microscopic examination.  If you have not done this or if the specimen has not been examined by an expert, please submit your record as genus only (Entoloma)

Short turf and lawns

Found from late spring to autumn

Widespread and common in Britain

Common in Leicestershire and Rutland.

https://www.first-nature.com/fungi/entoloma-conferendum.php