Lyophyllum shimeji, a species associated with lichen pine forest in northern Fennoscandia

Phylogenetic relationships of Lyophyllum section Difformia were inferred using internal transcribed spacer (ITS) and large sub-unit (LSU) sequence data of specimens from Fennoscandia and Japan. Sequence analyses show that the delicacy mushroom Lyophyllum shimeji, hitherto only known from East Asia, occurs in Fennoscandia and that it is confined to Scots pine forests on lichen-clad sandy soil. Also, Lyophyllum decastes and L. fumosum, two species described from Europe, have a wide distribution and are represented in Japan. Within both these species sequence variation indicates that more taxa should be recognized. The observed phylogenetic differences correlate strongly with habitat, conifer or deciduous forest, but also to some extent with geographic origin. The identity of the species Lyophyllum loricatum remains unclear and further sequences from specimens fitting the original description are needed to resolve its taxonomic status. The phylogenetic results suggest that ecology is an important character when discriminating between species in Lyophyllum section Difformia.