as Tricholoma pardinum (Secr.) Quél. Secretan's works are generally not recognised for nomenclatural purposes because he did not use binomial nomenclature consistently. There has been confusion over which scientific name to use for over two hundred years. Tricholoma tigrinum has been used in some European field guides, but has been applied in error to this species. The uncertainty was such that Czech mycologists Josef Herink and František Kotlaba suggested in 1967 that both are incorrect and proposed the new name T. pardalotum. Tricholoma pardinum lies within the subgenus Pardinicutis of Tricholoma, a grouping of similar species characterised by greyish, brownish, or pallid caps that are woolly or covered in small scales, spores with a length between eight and eleven micrometres, and abundant clamp connections in the hyphae. Molecular analyses suggest that T. pardinum is closely related to T. huronense, T. mutabile, and T. venenatum. Tricholoma pardinum var. filamentosum is an uncommon variety, described in 1983 by Carlo Luciano Alessio, which produces mushrooms with more fibrillose caps and stalks than the typical variety. It is found in southern Europe, where it associates with chestnut and spruce trees. Another variety has been described as T. pardinum var. unguentatum, characterised by daintier mushrooms that have a greasy coating on their caps. The specific epithet pardinum is derived from the Latin pardus "leopard", referring to its mottled or spotted cap. The generic name derives from Greek thrix "hair" (GEN trichos) and lōma "hem", "fringe", or "border". Common names include striped tricholoma, spotted tricholoma, tiger tricholoma, poison trich, leopard knight, and tigertop. Dirty trich was a name coined by author Gary H. Lincoff in response to a publisher's request for a more accessible name than its binomial one for North American guidebooks. Description The fruit body is a medium-sized mushroom, with a cap ranging from in diameter. The cap is initially hemispherical before flattening with maturity, and has a broad, shallow umbo. The cap margin is initially curled inwards but uncurls as it matures. The cap surface is silvery-grey and covered with concentrically patterned darker grey, brown or blackish scales that grow paler toward the cap margin, Secretan noting its resemblance to the cap of Sarcodon imbricatus. The gills are free (unattached to the stalk), white and thick, may have a yellow or greenish tint, and may drip water, as may the top of the stalk when broken. With age, the gill edges can become