(Singer & A.H. Sm.) Pierotti
Identity
Unique IDELEMENT_GLOBAL.57.9793
Element CodeNFSM000009
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryFungus
Endemicendemic to a single nation
KingdomFungi
PhylumBasidiomycota
ClassBasidiomycetes
OrderRussulales
FamilyRussulaceae
GenusLactarius
SynonymsArcangeliella crassaSinger & A.H. Sm.
Concept ReferenceCastellano, M. A., J. E. Smith, T. O'Dell, E. Cazares and S. Nugent. 1999. Handbook to strategy 1 fungal species in the Northwest Forest Plan. USDA Forest Service General Technical Report PNW-GTR-476. Northwest Research Station, Portland, OR. 195 pp. Online. Available: https://www.fs.usda.gov/pnw/pubs/pnw_gtr476.pdf
Taxonomic CommentsSpecies Fungorum (2018) transfers Arcangeliella crassa to Lactarius crassus.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2022-11-14
Change Date2022-11-14
Edition Date2022-11-14
Edition AuthorsFrancisco J. Camacho (2002), rev. C. Nordman (2022).
Threat ImpactMedium - low
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences21 - 80
Rank ReasonsLactarius crassus occurs in mountainous areas of the northwestern United States, it is widespread in the Sierra Nevada, the southern Cascade and Klamath ranges in California, and in the Cascade Range in Oregon. There are about 40 known occurrences, but more occurrences likely can be found with additional survey fieldwork. Threats are medium to low, and include extreme and prolonged drought, and high intensity wildland fire, and to a lesser extent, logging, but it can be found in young fir stands.
Range Extent CommentsLactarius crassus occurs in mountainous areas of the northwestern United States, it is widespread in the Sierra Nevada, the southern Cascade and Klamath ranges in California, and in the Cascade Range in Oregon. The range extent is estimated to be 129,000 square kilometers (MyCoPortal 2022, NatureServe 2022, Siegel et al. 2019).
Occurrences CommentsThere are estimated to be about 40 occurrences, including about 20 occurrences in Oregon and about 20 occurrences in California (NatureServe 2022, MyCoPortal 2022).
Threat Impact CommentsThis is a mycorrhizal species; it is dependent on a host tree for its carbohydrates. Studies have shown that if the tree is killed the mycorrhizal fungi can die shorty after, but this species does occur in young Abies stands. Severe and prolonged droughts and decades of fire suppression have drastically altered western montane forests, leading to thicker, denser, Abies dominated forests. As a result hotter, higher intensity wildland fires (rather than patchwork and understory burns) are more common, these fires can alter habitat drastically, and making it ill-suited for this species (Siegel 2022).