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Gastrolactarius camphoratus (Singer & A.H. Sm.) J.M. Vidal

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Scientific name
Gastrolactarius camphoratus
(Singer & A.H. Sm.) J.M. Vidal
Common names
IUCN Specialist Group
Cup-fungi, Truffles and Allies
Assessment status
Assessment date
IUCN Red List Category
IUCN Red List Criteria
A2c; C2a(i)
Castellano, M.
Dahlberg, A.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/75111171/75111471


An easily recognized hypogeous mycorrhizal fungus confined to old growth forests. Endemic to North America.

Known from a total of 24 sites from Canada and USA in Washington and Oregon, 11 sites are concentrated within a small geographic area in distance in Currey County along the southwest cost of Oregon. Three sites are historic and not re-documented for at least 30 years.

A large Biscuit forest fire in 2002 has probably significantly impacted the Currey county sites. Random Grid survey of 750 plots for two years across this region, including plots in this habitat type, revealed two new sites for this species in southwest Oregon. Listed as a sensitive species by the USDA Forest Service and the Bureau of Land Management in Oregon. Ranked as imperiled on the Global, National, and State rankings by the Oregon Heritage Program. Listed as critically imperiled (rank 1) by the Oregon Natural Heritage Information Center.

Gastrolactarius camphoratus is listed here as Endangered as it is thought to have undergone a 50% reduction in the past 50 years (three generations), the population size comprises an estimated 250 mature individuals and the size of the largest subpopulation is about 20 individuals and there is continuing decline because of the various threats to the habitat and host species.

Taxonomic notes

Originally described as Elasmomyces camphoratus by Singer and Smith (1960). Pegler and Young (1979) transferred it to Arcangeliella based on spore characteristics. Transferred to Gastrolactarius by Vidal (2004).

Geographic range

Endemic to western North America. Only known from Canada and USA in Washington and Oregon. In Canada, recorded  from a single site in southern British Columbia in the coast mountains physiographic province, east of Vancouver. In Washington from the Olympic Peninsula Physiographic province, east of Forks, Washington. In Oregon from both the Oregon coast and Oregon Klamath physiographic provinces along the central coast and south coast of Oregon.

Population and Trends

 In total, 24 known sites from British Columbia, Canada south to southeast coast of Oregon. One location is from southern BC, two sites (one location) from the Olympic Peninsula, 20 sites (one location) from southwest Oregon coastal forests, one site inland in Benton County, Oregon. Eleven of 24 (46%) known sites potentially extirpated by Biscuit forest fire 2002 (https://en.wikipedia.org/wiki/Biscuit_Fire). Two other known sites not recollected in over 30 years even though specifically searched for numerous times since first recorded.

Listed as a sensitive species by the USDA Forest Service and the Bureau of Land Management in Oregon  (Oregon Biodiversity Information Centre 2013). Ranked as Imperiled on the Global, National, and State rankings by the Oregon Heritage Program. Listed as Critically Imperiled (rank S1) by the Oregon Natural Heritage Information Center.

Population Trend: decreasing

Habitat and Ecology

This is a mycorrhizal fungus species so it is dependent on living host trees for population viability. This mutually beneficial, symbiotic association between fungus and plant host roots conveys numerous critical advantages for plant host survival. Mycorrhizal fungi are essentially the uptake organs for many nutrients i.e., nitrogen, phosphorus, numerous micronutrients, i.e., boron, selenium, copper, and plays a major role in uptake of water. Both the fungus and the plant host does not exist in nature without each other.

This  species is associated with the roots of Western Hemlock (Tsuga heterophylla) and possibly Sitka Spruce (Picea sitchensis) from sea level to 3,039 ft (1,013 m) elevation. Fruiting January through March, June, and September through November. Dispersal is dependent on mycophagy (Castellano et al. 1999, Trappe and Castellano 2000). Home range of primary spore vector (small mammals) is less than 2 ha.

Easily recognized by its sequestrate habit, dark reddish-brown peridium, a gleba that exudes latex, and the somewhat exposed loculate-lamellate gills near the base. Upon drying specimens have a strong and distinct odour of maple syrup similar to Lactarius fragilis.


This is a mycorrhizal fungus species so it is dependent on living host trees for population viability. Both the fungus and the plant host does not exist in nature without each other.

Mature old-growth Tsuga heterophylla and Picea sitchensis forests are routinely harvested for wood products that has led to some forest fragmentation that may impede fungus dispersal and gene flow.  In addition, these coastal mountain forests are subject to logging, clearing of land for agricultural use, intense forest fires, and disturbance from human activities, i.e., road building, home construction, and campground development. Global climate change is potentially devastating to low elevation coastal forests in western North America.

The Biscuit forest fire of 2002 may have negatively impacted known sites along the southeast coast of Oregon (http://en.wikipedia.org/wiki/Biscuit_Fire).  This fire burned over 2,000 km2, almost 197,000 ha in northern California and southeast Oregon across as many as 11 known sites for this species on the Rogue River-Siskiyou National Forest have been potentially negatively impacted.

This species has highly isolated occurrences in southwestern British Columbia, western Washington, and southwestern Oregon with little potential for gene flow between them.  Extensive logging has removed most of the mature to old-growth coastal forests in Oregon and Washington thereby removing potential habitat for this species.  ntensive recreational use of forested public lands along the Oregon and Washington coasts may also have an impact on species viability due to trampling, soil compaction, and other types of human disturbance.

Conservation Actions

It is important to protect known sites. Known sites should be buffered from ground and host disturbances. Revisit known sites to confirm persistence and determine extent of populations, particularly for known sites more than 30 years old. Mitigate impacts during vegetation management in or near known sites.

Use and Trade

Is a truffle-like fungus so presumably is edible,

Source and Citation

Castellano, M. 2015. Gastrolactarius camphoratus. The IUCN Red List of Threatened Species 2015: e.T75111171A75111471. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T75111171A75111471.en .Accessed on 8 February 2024

Country occurrence