SPECIES FACT SHEET
Scientific name: Rhizopogon brunneifobrillosus A.H. Smith
Family: Rhizopogonaceae
Division: Eumycota
Subdivision: Basidiomycotina
Class: Gasteromycetes
Order: Hymenogastrales
Family: Rhizopogonaceae
Species is new to the Sensitive and Special Status Species list and is not
addressed in the Fungi Conservation Assessment. It does not have status
under the Survey and Manage Standards and Guidelines, and hence
Management Recommendations previously created for those species do
not cover this species.
Conservation Rankings and Status:
Global: G2G3
State: OR S1, WA Not ranked
Oregon Biodiversity Information Center (ORBIC) List: 2
(Ranks from ORBIC, http://orbic.pdx.edu accessed August 16, 2013)
Type Locality: Bear Springs area, Mt. Hood National Forest, Oregon
Type: Smith 68592
Technical Description: Rhizopogon brunneifibrillosus is distinct by
having nongelatinous hyphae in the tramal plates and yellow-brown
hymenial and subhymenial elements for the most part. It is close to R.
gilkyae in some respects but differs sharply in the well-developed peridial
epicutis, in the narrower spores, and in that the peridium does not flake
off.
Fruiting bodies about 3 cm. diameter, subglobose, surface dry and
unpolished from a loosely-fibrillose layer, with a basal cluster of
rhizomorphs, dark cinnamon-brown (±”cinnamon brown” as dried),
darker when rubbed (dark russet in these areas finally, and as dried),
darker brown with KOH, FeSO4 slowly blackish, FeSO4 following a drop of
ethanol quickly blackish. Gleba firm as dried but not hard, in sectioning
rather crumbly, chambers distinct, dull sepia as dried. Spores 7-8.5 X
2.2-2.5 µ, oblong, smooth, mostly ochraceous-hyaline in KOH singly,
dark yellow-brown in groups; in Melzer’s solution yellowish singly, in
masses reddish brown, typically with a false septum, basal truncation
present but obscure. Basidia clavate, 8-spored, 8-10 µ broad, with
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yellow-brown walls as revived in KOH and Melzer’s solution, not at all
gelatinous. Paraphyses clavate to vesiculose, 8-10 µ diameter, thinwalled, walls yellow-brown in KOH and not at all gelatinous, content
homogeneous or with a poorly defined amorphous central body (but not
thick walled as in R. villosulus). Tramal plates of nongelatinous hyaline
to slightly yellow-brown interwoven hyphae 4-9 µ diameter no pigment
incrustations seen; subhymenium cellular, the cells with hyaline to
yellow-brown walls, not at all gelatinous, content similar to that of
paraphyses. Peridium with a very well developed epicutis of loosely
interwoven smooth walled rusty-brown (in KOH) hyphae mostly with
walls at least somewhat thickened and cells equal to inflated, cells
mostly 6-12 µ broad, but some inflated cells up to 50 µ and some
narrowed hyphal tips 2-3 µ diameter, some inflated cells in the layer,
orange-brown pigment balls present in mounts in Melzer’s solution. No
olive seen anywhere in KOH, very little amyloid debris present. Clamps
none.
Rhizopogon brunneifibrillosus is closely related to the common R.
villosulus and the rare R. quercicola and is distinguished from them
primarily by the lack of an olive-green staining reaction of peridial tissue
in a KOH. Trappe observes that this trait is not pervasive throughout the
peridium, but is rather patchy. He suggests that the differences between
these three species are so subtle and minute (spore dimensions, peridial
reactions to KOH) that it is possible the complex actually is only one
variable species.
Rhizopogon is one of several genera included among the “false truffles.”
There are perhaps four groups of fleshy fungi with which species of
Rhizopogon are likely to be confused: 1) puffballs, 2) gastroid agarics, 3)
other “false truffle” genera, and 4) true truffles. False truffles, puffballs,
and gastroid agarics are included within the Gasteromycetes – basidiumproducing fungi whose spores are produced internally and not forcibly
discharged from the basidia. The spore mass of puffballs (Lycoperdon
and allies) is usually white, firm, and without readily discernable
chambers when young, and becoming powdery and rather quickly
dispersed at maturity. The fruiting bodies of puffballs are usually found
aboveground. While the presence of a cap and stalk is clearly evident in
some gastroid agarics, species of Endoptychum, Brauniellula or
Thaxterogaster may bear a stronger resemblance to false truffles.
However, dissection of a gastroid agaric will reveal at least some evidence
of a percurrent stalk (one that extends through the spore mass to the top
of the cap). At maturity, the sporocarps of gastroid agarics are usually
found partially or fully aboveground. Among other genera of false truffles
(e.g., Alpova, Gautieria, Hydnangium, Hymenogaster, Hysterangium,
Leucophleps, Martellia and Truncocolumella), Rhizopogon generally is
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distinct in exhibiting the following set of features: 1) an exterior surface
often overlain with soft mycelial strands (rhizomorphs), 2) spore mass
composed of minute, generally non-gelatinous chambers (best seen with
hand lens), 3) stalk (basal and within spore mass) typically lacking and
4) spore surfaces smooth. Microscopically, true truffles are readily
differentiated from species of Rhizopogon by the presence of sexually
produced spores borne within asci. Macroscopically, however, fruiting
bodies of true truffles will, as is typically true of Rhizopogon, show no
evidence of a stalk, either basal, or within the spore mass. The interior of
a true truffle, however, will typically differ from that of Rhizopogon
species in being either 1) solid and marbled with veins, or 2) completely
hollow or with quite evident folds and chambers. Because of the need to
recognize multiple, subtle, microscopic anatomical features and use
chemical staining procedures, it is probably unrealistic to expect a lay
mycologist to do more than recognize that a fleshy fungus specimen is
likely to be included in the genus Rhizopogon. Identification to species
will almost certainly require the services of a Rhizopogon "expert".
Life History: Fruits in the fall. This species is ectomycorrhizal with
Pseudotsuga and probably other Pinaceae and depends on mycophagy
(consumption by animals) for spore dispersal.
Range, Distribution, and Abundance: Known from only two collections,
both in the Bear Springs area on the southeast slope of Mt. Hood, Mt.
Hood National Forest, Wasco County, Oregon, in the Eastern Cascades
Physiographic Province. The type specimen was collected in October
1964 and one sporocarp was collected in October 2009. The 2009
collection is located about 50 m north of Highway 216 and 50 m west of
Spring Drive (UTM 10T 616616.65 E, 4996850.15 N) at 3,176 feet
elevation. Also reported from Idaho (ORBIC).
FS/BLM lands where documented: Mt. Hood NF
Habitat Associations: Type specimen found as a single sporocarp in
duff under mixed conifers. Trappe #33905 specimen found under a small
Pinus ponderosa tree among Abies concolor, Pseutotsuga menziesii, and
snowbrush.
Threats: With the assumption that this species is ectomycorrhizal, it is
reasonable to assume that as with ectomycorrhizal fungi in general,
threats to the species are activities or events that result in direct or
indirect impacts to fungal individuals or mycelial mats. These threats
include activities that:

remove or destroy the fungal organism
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intensively or extensively remove or consume the woody substrate,
forest floor litter, or tree or shrub hosts with which the species is
associated
remove trees or other vegetation that significantly modifies the
microclimate at the species’ site
compact soil or change soil chemistry
Impacts to fungal organisms can reduce both the biomass and species
diversity within a community of ectomycorrhizal fungi. Attendant
reductions in production of false truffles may, in turn, potentially reduce
dispersal of their spores by small mammals. Fire is not a potential threat
to Rhizopogon brunneifobrillosus because the general habitat where it
occurs is cool and wet and not prone to fires. However, if fire were to
occur, particularly a hot ground fire, it could harm populations from
disturbance to soil or by damaging host trees. Climate change may result
in a decline of vigor and may result in extirpation of this species. An
increase in temperature or a decrease in precipitation could affect
disjunct populations.
Conservation Considerations: Revisit documented site to reconfirm
presence and better define habitat. Conduct surveys to locate new
populations on federal land. Buffer known sites and protect from wildfire;
prescribed burns; vegetation management projects that would remove
potential host plants, disturb soil or duff, or change habitat or
microclimate conditions; and ground-disturbing activities (e.g.,
recreational vehicles, road building, grazing) that would reduce moistureretaining ground covers. Consider vegetation management activities
within known site buffers that are likely to maintain or improve
ectomycorrhizal fungal habitat quality (e.g. moderate hand-thinning of an
overstocked stand or augmenting a deficient volume of coarse woody
debris). When conducting vegetation management activities in areas with
good habitat potential, consider leaving scattered and clumped host trees
and ample coarse woody debris while minimizing soil compaction and
burn severity of activity-related fires.
As a mycorrhizal species, Rhizopogon brunneifobrillosus forms symbiotic
associations with the fine root systems of plants, growing out into the
soil matrix. To provide a reasonable assurance of the continued
persistence of occupied sites consider incorporation of patch retention
areas (as described in Standards and Guidelines 1994, C-41) with
occupied sites wherever possible.
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Other pertinent information (includes references to Survey
Protocols, etc): The survey protocol for fungi is located on the ISSSSP
website:
http://www.fs.fed.us/r6/sfpnw/issssp/documents/inventories/inv-spfu-ver1-2008-12.pdf.
Prepared by: Marcia Wineteer, Medford BLM
Date: April 2013
Edited by: Rob Huff, BLM/FS Portland, Oregon
Date: January 2014
ATTACHMENTS:
(1)
References
(2)
Map of Species Distribution
(3)
Photographs of Species
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ATTACHMENT 1:
References
Arora, David. 1979. Mushrooms Demystified – A Comprehensive Guide to
the Fleshy Fungi. Ten Speed Press, Berekeley, California. 959 pp.
Cushman, Kathleen and Rob Huff. 2007. Conservation Assessment for
Fungi Included in Forest Service Regions 5 and 6 Sensitive and BLM
California, Oregon and Washington Special Status Species Programs. R6
USFS and OR/WA BLM Interagency Special Status/Sensitive Species
Program (ISSSSP).
http://www.fs.fed.us/r6/sfpnw/issssp/planning-tools/
Ferriel, Jenifer and Katie Grenier. 2008. Annotated Bibliography of
Information Potentially Pertaining to Management of Rare Fungi on the
Special Status Species List for California, Oregon and Washington.
R6USFS and OR/WA BLM Interagency Special Status/Sensitive Species
Program (ISSSSP).
http://www.fs.fed.us/r6/sfpnw/issssp/planning-tools/
Oregon Biodiversity Information Center. 2010. Rare, threatened and
endangered species of Oregon. Oregon Biodiversity Information Center,
Institute for Natural Resources, Oregon State University, Portland,
Oregon. 105pp.
http://orbic.pdx.edu/documents/2010-rte-book.pdf
Smith, Alexander H. and S.M. Zeller. 1966. A Preliminary Account of the
North American Species of Rhizopogon in Memoirs of The New York
Botanical Garden, Vol. 14, No. 2, March 15, 1966.
Trappe, Matthew J. 2009. State Historic Fungal Survey, Bear Springs,
Fall 2009, Mt. Hood National Forest. Final Report, November 20, 2009.
On file at Oregon State Office, Bureau of Land Management. 8 pp.
Trappe, James M., Randy Molina, Daniel L. Luoma, Efren Cazares, David
Pilz, Jane E. Smith, Michael A. Castellano, Steven L. Miller, and Matthew
J. Trappe. Diversity, Ecology, and Conservation of Truffle Fungi in Forests
of the Pacific Northwest. 2009. PNW-GTR-772. 202 pages.
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ATTACHMENT 2:
Map of Species Distribution in OR/WA
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ATTACHMENT 3:
Photograph of species
Photo by Matt Trappe, used by permission.
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