Tricholoma pardinum, commonly known as spotted tricholoma, tiger tricholoma, tigertop, leopard knight, or dirty trich, is a gilled mushroom widely distributed across North America, Europe, and parts of Asia. It is generally found in beech woodland in summer and autumn. Two subspecies have been described from southern Europe. First officially described by Christiaan Hendrik Persoon in 1801, T. pardinum has had a confusing taxonomic history that extends over two centuries. In 1762, German naturalist Jacob Christian Schäffer described the species Agaricus tigrinus with an illustration corresponding to what is thought to be T. pardinum, and consequently, the name Tricholoma tigrinum has been used erroneously in some European field guides. The fruit body of Tricholoma pardinum is an imposing mushroom with a pale grey cap up to in diameter that is covered with dark brownish to greyish scales. The gills are whitish, and are not attached to the stout white to pale grey-brown stalk. The spore print is white. One of the more toxic members of the genus Tricholoma, the species has been implicated in a number of episodes of mushroom poisoning, probably because it is a large, attractive mushroom with a pleasant smell and taste, and it bears a superficial resemblance to several edible species, like Tricholoma terreum. Ingesting T. pardinum—even in small quantities—results in a severe, persistent gastroenteritis caused by an unknown mycotoxin. Taxonomy The German naturalist Jacob Christian Schäffer published Fungorum qui in Bavaria et Palatinatu circa Ratisbonam nascuntur Icones in 1762, in which he described a mushroom he called Agaricus tigrinus. The illustration accompanying the name fits what we now know as Tricholoma pardinum; the description is less clear. Elias Magnus Fries used the name Agaricus tigrinus in his 1821 work Systema Mycologicum, in accordance with Bulliard's 1782 description, which now corresponds with Lentinus tigrinus. Christiaan Hendrik Persoon described this species as Agaricus myomyces var. pardinus in 1801, but queried whether it was a distinct species. In his 1838 work Epicrisis systematis mycologici: seu synopsis hymenomycetum, Fries assigned a different fungus again to the binomial name and linked it to Schäffer's 1762 description. French mycologist Lucien Quélet reclassified it as a species in 1873, giving it its current binomial name. Italian mycologist Alfredo Riva has noted that Swiss mycologist Louis Secretan provided a description forty years before Quélet, in his 1833 work Mycographie Suisse, and queried why it was ignored. He has proposed the fungus be written