Agaricus? if so, which please?

Agaricus? if so, which please?

Observation - Agaricus? if so, which please? - UK and Ireland. Description: 16cm tall. gills off-white. bell shaped and scaly cap approx 6cm wide. veil. found in old hay meadow. single specimen.

16cm tall. gills off-white. bell shaped and scaly cap approx 6cm wide. veil.
found in old hay meadow. single specimen.