What is "amanitas"

Usage examples of "amanitas".

But from what I had read I surmised that it must be that one of the poisonous varieties had somehow got mixed with the others, one of the Amanitas, just as deadly as the venom of the rattler or the copperhead.

Think not of a sweet, white mushroom for soup, but of red amanitas that erupt after rain like erect penises—like the member of Cernunnos/Satan.