Blackening brittlegill

Blackening brittlegill (Russula nigricans) is one of those confusing fungi that start off one colour (dirty white), shade into another (grey-brown) and eventually turn black. Its better identified from its gills. These are really widely spaced and liable to disintegrate at the lightest touch - hence the name. Best of all, if you cut it open the flesh turns red. Loads of them in the woods around here at the moment.