New reports, phylogenetic analysis, and a key to Lactarius Pers. in the Greater Yellowstone Ecosystem informed by molecular data

Edward G Barge,Cathy L Cripps

doi:10.3897/mycokeys.15.9587

Abstract

The Greater Yellowstone Ecosystem (GYE), located in the Central Rocky Mountains of western North America, is one of the largest nearly intact temperate-zone ecosystems on Earth. Here, Lactarius is an important component of ectomycorrhizal communities in many habitat types, from low elevation riparian areas to high elevation conifer forests and alpine tundra. Molecular phylogenetic analyses of ITS and RPB2 gene sequences along with detailed morphological examination confirm at least 20 Lactarius species, as well as three varieties, and one unresolved species group in the GYE. Eight taxa are reported from the GYE for the first time, and nearly every major ectomycorrhizal host plant in the GYE appears to have at least one Lactarius species associated with it. Broad intercontinental distributions are suggested for alpine Salix and Betula associates, and for certain subalpine Picea and aspen (Populus spp.) associates. Some species appear to be restricted to western North America with Pinus, Pseudotsuga or Abies. The distribution and/or host affinities of others is not clear due in part to ambiguous host assignment, taxonomic problems or the relative rarity with which they have been reported.

Highlights

The Greater Yellowstone Ecosystem (GYE), located in the Central Rocky Mountains of North America, is one of the largest nearly intact temperate-zone ecosystems on Earth
The first publicly available vouchered sequences are provided for L. alpinus v. mitis, L. lapponicus, L. pseudodelicatus, and L. zonarius v. riparius; the first publicly available vouchered sequences from North America are provided for L. badiosanguineus, L. aff. brunneoviolaceus, L. aff. olivinus, and L. aff. tuomikoskii
Previous reports of L. uvidus from the GYE (McKnight 1982) and the Central and Southern Rocky Mountains in general likely refer to L. montanus

Summary

Introduction

The Greater Yellowstone Ecosystem (GYE), located in the Central Rocky Mountains of North America, is one of the largest nearly intact temperate-zone ecosystems on Earth. While a definitive boundary does not exist, the GYE roughly includes Yellowstone National Park at its center, Grand Teton National Park, and portions of surrounding national forests and other lands in Montana, Wyoming, and Idaho (Keiter and Boyce 1991) (Figure 1). Includes species with sporocarps that exude a milky latex when damaged, in addition to the amyloid ornamented basidiospores characteristic of the family. The original genus is recognized as nonmonophyletic and has been split into three genera within Russulaceae: Lactarius, Lactifluus (Pers.) Roussel, and Multifurca Buyck & Hoffstetter (Buyck et al 2008, 2010); approximately 80% of the traditional species are still retained in Lactarius sensu stricto (Verbeken and Nuytinck 2013)

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Results

Conclusion