E-Flora BC: Electronic Atlas of the Flora of British Columbia

Ganoderma oregonense Murrill
western varnished conk

Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.

Introduction to the Macrofungi

© Celeste Paley  Email the photographer   (Photo ID #75153)

E-Flora BC Static Map
Distribution of Ganoderma oregonense
Click here to view the full interactive map and legend
Details about map content are available here
Click on the map dots to view record details.

Species Information

Ganoderma oregonense forms large yellow-brown to red-brown semicircular or fan-shaped brackets with a lacquer-like surface, growing on conifers. Many consider this a synonym of Ganoderma tsugae Murrill, Bull. Torrey bot. Club 29: 601. 1902. Gilbertson(1) distinguish them on the following features [while saying they are doubtfully distinct]: Ganoderma oregonense has a cap up to 100cm x 40cm x 20cm, 2-3 pores / millimeter, and spores 13-17 x 8-10 microns, whereas Ganoderma tsugae has cap up to 20cm x 30cm x 7cm, 5-6 pores per millimeter, and spores 13-15 x 7.5-8.5 microns, (Ginns(25)). Ganoderma oregonense is found in BC, WA, OR, ID, and also CA, MT, and NV.
up to 100cm across, 40cm wide, 20cm thick, semicircular or fan-shaped; "yellowy brown to dark reddish brown or mahogany, with concentric bands of color; quickly develops a shiny, waxy crust that cracks extensively in older specimens", (Phillips), up to 100cm wide, 40cm deep, and 20cm thick, without a stem or with a rudimentary lateral stem, single or occasionally imbricate [shingled], annual; upper surface ochraceous to dark reddish brown or mahogany, often distinctly concentrically zoned; quickly developing shiny lacquered crust, crust cracking extensively on older specimens, (Gilbertson)
up to 15cm thick, "soft-fibrous; cream-colored to pale buff", (Phillips), up to 15cm thick, "soft-fibrous, homogeneous and azonate or with a thin firmer layer with thin darker lines directly under the surface crust", cream-colored to pale buff, (Gilbertson)
2-3 per mm, circular to angular; cream colored bruising brown or purplish brown; tube layer up to 3cm thick, pale purplish brown, (Phillips), 2-3 per mm, circular to angular, with thin entire walls; "cream colored at first, bruising or drying wood brown to pale purplish brown"; tube layer up to 3cm thick, distinct from flesh, pale purplish brown, (Gilbertson)
with no stem or small lateral stem-like attachment (Phillips)
none (Miller)
unknown (Miller)
spores 13-17 x 8-10 microns, elliptic, with truncate apex, inamyloid, pale brown in KOH, "wall with two layers separated by interwall pillars, outer wall with pronounced depressions and appearing rough"; cystidia absent; hyphal system trimitic: context generative hyphae 2.5-5 microns wide, "thin-walled, with clamps, rarely branched"; context skeletal hyphae 3-5 microns wide, colorless, thick-walled, non-septate, with occasional branching, context binding hyphae 2-4.5 microns wide, colorless, thick-walled, non-septate, with frequent branching, trama hyphae similar; cap surface with dense palisade of clavate, thick-walled strongly amyloid end cells, up to 70 microns long and 8.5-11 microns wide at widest point, (Gilbertson)
Spore Deposit:
rusty brown (Phillips, Gilbertson)

Habitat / Range

annual, commonly on dead standing conifers and on conifer stumps, main substrates are Abies (fir) and Tsuga (hemlock), causes white butt and root rot of living and dead conifers, (Gilbertson), fruiting in spring, summer, and fall, (Miller)

Synonyms and Alternate Names

Ganoderma sequoiae Murrill

Taxonomic and Nomenclatural Links

Additional Range and Status Information Links


no (Phillips)

Additional Photo Sources

Related Databases

Species References

Gilbertson(1), Phillips(1)*, Miller(14)*, Ginns(25), Trudell(4)*, AroraPocket*

References for the fungi

General References