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Destuntzia rubra (Harkn.) Fogel & Trappe

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Scientific name
Destuntzia rubra
Author
(Harkn.) Fogel & Trappe
Common names
 
IUCN Specialist Group
Cup-fungi, Truffles and Allies
Kingdom
Fungi
Phylum
Basidiomycota
Class
Agaricomycetes
Order
Gomphales
Family
Gomphaceae
Assessment status
Published
Assessment date
2015-04-27
IUCN Red List Category
CR
IUCN Red List Criteria
C2a(i)
Assessors
Castellano, M.
Reviewers
Dahlberg, A.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/75102369/75721162

Justification

Easily recognized by its truffle-like habit, white peridium that oxidizes or bruises pink to red instantly, a gleba marbled white and dark brown-black, and distinctly fishy odour of fresh specimens.  Endemic to California and Oregon, and apparently restricted to dryer sites in the San Francisco Bay area and the low foothills of the Sierra Nevada mountains and the Klamath Mountains. An extensive survey of historic known sites has not revealed new collections. Originally reported from the San Francisco Bay area, but not seen in that area in 40 years. Occurrence at the two original sites in Oregon have not been re-documented for at least 30 years. Extensive surveys of potential habitat revealed five recent sites, but an extensive Random Grid survey of 750 plots in the region did not reveal any new collections or sites for this species. Listed as a sensitive species by the USDA Forest Service and the Bureau of Land Management in Oregon. Ranked as Imperiled (G2) on the Global, National, and State rankings by the Oregon Heritage Program. Was listed as Critically Imperiled (rank S1) by the Oregon Natural Heritage Information Center in 2013, but in 2015 is  listed as Possibly Extirpated or Extinct (SH) (NatureServe 2015).

Destuntzia rubra is listed here as Critically Endangered under criterion C2a(i) because of the small population size (about 200 mature individuals and with no more than 10 individuals in each subpopulation and a continuing decline due to loss and degradation of its habitat.



Taxonomic notes

Originally described as Hymenogaster ruber by Harkness (1899). It was recombined as Destuntzia rubra (Harkn.) Fogel (1985). Fogel (1985) lists Hymenogaster versicolor Harkness as a synonym.

Geographic range

Endemic to Oregon and California (United States). Apparently restricted to dryer sites in the San Francisco Bay area and the low foothills of the Sierra Nevada mountains and the Klamath Mountains. Known from 13 total sites, but the species has not been reported from eight of these sites in over 30 years despite continued surveys in and around these localities.


Population and Trends

Known from 13 total sites, but eight of these are older than 30 years and specimens have not been found in or near them since, despite continued survey for them in the interveening years. This is a loss of 61.5% of the known sites in 30 years. An extensive Random Grid survey of 750 plots in the region did not reveal any new collections or sites for this species (Castellano 2007).  It is estimated that there are no more than 10 mature individuals in a subpopulation.  The species is hypogeous and depends on mycophagy (eaten by small mammals) for spore dispersal, which greatly limits the dispersal area.

Population Trend: decreasing


Habitat and Ecology

Hypogeous, mycorrhizal sequestrate species associated with the roots of Pseudotsuga menziesii.  Most known sites are located below 600 m elevation.  Fruiting March through July and October through December.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.


Threats

The species grows in mature old-growth forests dominated by Pseudotsuga menziesii which are encroached upon by urban development in the San Francisco Bay area from where this species was originally discovered.  Urban development along the California coast has led to some forest fragmentation that may impede fungus dispersal and gene flow. In addition, these Pseudotsuga menziesii forests are subject to logging, clearing of land for agricultural use, and disturbance from human activities, i.e., road building, home construction, and campground development.  The only known inland site occurs in a highly used Forest Service campground. Global climate change is potentially devastating to low elevation coastal forests in western North America.



Conservation Actions

Protect known sites from management activities and encroachment of urban development.

Use and Trade

Is truffle-like, so might be eaten.

Source and Citation

Castellano, M. 2015. Destuntzia rubra. The IUCN Red List of Threatened Species 2015: e.T75102369A75721162. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T75102369A75721162.en .Accessed on 1 February 2022

Country occurrence