Circumscription of species in the Hodophilus foetens complex (Clavariaceae, Agaricales) in Europe

Four European Hodophilus species with an odour similar to naphthalene, a strong unpleasant odour similar to that of mothballs, are recognized based on sequence and/or morphological data. The traditional concept defines Ho. foetens as the only Hodophilus species with a naphthalene odour in Europe. This name is now assigned to one of the studied species based on morphological examination of the holotype specimen. A recently collected specimen is proposed as the epitype. The other three species with a naphthalene odour are described here as new: Ho. pallidus , Ho. subfoetens and Ho. tenuicystidiatus. They are distinguishable in the field based on a combination of lamellae number and colour of basidiomata. All four species are grouped in the Ho. foetens superclade, one of two superclades, together with the Ho. micaceus superclade, in the genus Hodophilus . All are different species from North American taxa with a naphthalene-like odour recognised in a previous study. The Ho. foetens superclade also includes one species identified as Ho. atropunctus that does not have a distinctive odour. The type collection of Ho. albofloccipes , a recently described European species with a naphthalene odour, is placed together with some collections without a distinctive odour in the Ho. micaceus superclade.