Amanita alpinicola sp. nov., associated with Pinus albicaulis, a western 5-needle pine

A new species, Amanita alpinicola, is proposed for specimens fruiting under high elevation pines in Montana, conspecific with specimens from Idaho previously described under the invalid name, "Amanita alpina A.H. Sm., nom. prov." Montana specimens originated from five-needle whitebark pine (Pinus albicaulis) forests where they fruit in late spring to early summer soon after snow melt; sporocarps are found mostly half-buried in soil. The pileus is cream to pale yellow with innate patches of volval tissue, the annulus is sporadic, and the volva is present as a tidy cup situated below ragged tissue on the stipe. Analysis of the ITS region places the new species in A. sect Amanita and separates it from A. gemmata, A. pantherina, A. aprica, and the A. muscaria group; it is closest to the A. muscaria group.