The species was originally described as Agaricus portentosus by Elias Magnus Fries in 1821,[5] before being placed in the genus Tricholoma by Lucien Quélet in 1872.

[8] The species epithet, portentosum, comes from the Latin portentosus, meaning marvellous or prodigious, and describes its taste.

The fruit bodies appear in late autumn in coniferous woodland in Europe and North America.

[4] The inedible Tricholoma virgatum has a silvery-grey cap and grows in mixed woodland, and smells of damp earth and has a bitter taste.

[14] The poisonous Tricholoma pardinum has prominent grey scales giving the cap a shaggy or striped appearance.

[20] In North America, it is common in the east,[23] notably in Quebec,[24] New Hampshire, Maine, Massachusetts, and in Connecticut.