The unexpected ecological plasticity of Phlegmacium herculeum (Malençon) Bellanger & P.-A. Moreau, comb. nov

Due to conspicuous morphological features and a strict association with cedar trees, Phlegmacium herculeum has long thought to be one of the easiest Cortinarius to diagnose in the field. Recent collections with a deviant morphotype fruiting under Pinus trees, yet phylogenetically representing this species, are here introduced as Phlegmacium herculeum f. pinophilum. The combination Phlegmacium herculeum previously introduced was invalid and is validated here. Ecological interpretations of the discovery of a new host for P. herculeum are discussed.