The king stropharia can grow to 20 cm high with a reddish-brown convex to flattening cap up to 30 cm across, the size leading to another colloquial name godzilla mushroom. The gills are initially pale, then grey, and finally dark purple-brown in colour. The firm flesh is white, as is the tall stem which bears a wrinkled ring. This is the origin of the specific epithet which means "wrinkled-ringed".
It is found on wood chips across North America in summer and autumn. Described as very tasty by some authors, king stropharia is easily cultivated on a medium similar to that on which it grows naturally. Antonio Carluccio recommends sautéeing them in butter or grilling them.
https://en.wikipedia.org/wiki/Stropharia_rugosoannulata