Two new species of Suillus associated with larches in China

Two Suillus species from China, S. alpinus and S. aurihymenius, are described as new. Both S. alpinus, a subalpine species currently known only from southwestern China, and S. aurihymenius, a boreal species from northeast China, are strictly associated with larches and morphologically similar to the European S. tridentinus by having a viscid squamulose pileus and veiled stipe. Suillus alpinus is distinguished by a much duller basidiome, paler orange pores, a faint bluish discoloration of the context, and a heavily reticulate stipe apex, while S. aurihymenius has a reddish gold hymenium, a context that discolors a deep reddish brown, and a less squamulose pileus. The identities of the two new species and their affinity with S. tridentinus are supported by ITS-rDNA sequence analyses. Suillus tridentinus, S. alpinus, and S. aurihymenius form a monophyletic clade representing a morphologically similar European-Asian temperate lineage associated with Larix.