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

Summary:
Features of Ganoderma tsugae include 1) a fairly large, fan-shaped to semicircular, reddish brown to mahogany or nearly black cap with a surface that has a varnished appearance, 2) a stem that may be absent or lateral and often vertical, the surface similar to the cap, 3) soft, spongy, light-weight flesh, that is cream to pale buff, often with thin black lines just below the cap surface, 4) round to angular pores, 5-6 per mm, the pore surface cream, 5) pale purplish brown tubes, 6) growth on conifers, and 7) microscopic characters including spores 11-12.5 x 6.5-8.5 microns. Note the discrepancy in spore sizes - those of Ginns(28) were taken from Adaskaveg and Gilbertson''s 1986 detailed study of G. tsugae. A. and O. Ceska reported a collection that in a fresh state had a bluish green cap (Mushroom Observer 333487). A blue Ganoderma was also reported on Facebook, apparently from Cortez Island in British Columbia by Kari Chase McNabb.

Ganoderma tsugae is known from BC (Ginns(28)), NS, ON, QC, AZ, CA, GA, IN, LA, MA, ME, MI, MN, NC, NH, NJ, NY, OH, PA, TN, TX, VA, VT, WI, and WV (Gilbertson). There are online records at the Consortium of Pacific Northwest Herbaria from Washington, Oregon, Idaho, and Alaska but without enough information to know if Ganoderma oregonense was being represented by the collector as a synonym of Ganoderma tsugae - additional herbarium notes on some of these collections are not online.

Cap:
up to 30cm along substrate, projecting up to 20cm (not including stem if present), up to 6.5cm thick, applanate (flattened), dimidiate (semicircular) to flabelliform (fan-shaped), reddish brown to mahogany; surface appearing varnished, smooth to wrinkled, (Ginns), up to 30cm along substrate, projecting up to 20cm (not including stem if present), up to 7cm thick, applanate, dimidiate to flabelliform; "quickly becoming reddish brown to mahogany"; with a highly varnished, thin crust, smooth to irregularly wrinkled, often with a rusty brown spore deposit on top, (Gilbertson)

Flesh:
up to 5cm thick, "soft and spongy"; "cream to pale buff, slightly darker next to the tube layer, often with thin black lines just below the varnished surface", (Ginns), up to 5cm thick, cream to pale buff, "azonate but with a slightly darker layer next to the tubes, upper region soft and spongy, lower part corky when dried", "thin black layers often present in context just below the cuticular layer"; in stem context continuous and concolorous with that of cap, azonate, homogeneous, (Gilbertson)

Pores:
5-6 per mm, "round to angular", "edges smooth, thin to thick"; pore surface cream; tubes up to 1.5cm deep, pale purplish brown, (Ginns), 5-6 per mm, "circular to angular", "with thick to thin, entire dissepiments", pore surface cream when fresh, "bruising or drying ochraceous to light brown"; tube layer up to 1.5cm thick, pale purplish brown, (Gilbertson)

Stem:
if present, stem up to 9cm long and 5cm wide, "lateral, often vertical", "reddish brown to mahogany or nearly black"; surface appearing varnished, (Ginns), attached laterally or absent, up to 9cm long and 5cm wide, "usually lateral, often vertical and well developed", surface developing a highly varnished crust, reddish brown to mahogany or almost black, (Gilbertson)

Microscopic:
spores 11.0-12.5 x 6.5-8.5 microns, ovoid with a truncated apex; generative hyphae 3-5 microns wide with clamp connections, skeletal hyphae 3.0-8.5 microns wide, walls colorless, binding hyphae 2-4 microns wide, dendritic, walls colorless, (Ginns), spores 13-15 x 7.5-8.5 microns, elliptic with truncate apex, pale brown in KOH, inamyloid, "wall two layered with interwall pillars between the layers, outer wall with pronounced depressions and appearing rough"; basidia 4-spored, 23-28 x 11-14 microns, "broadly clavate to pyriform", with a basal clamp connection; cystidia "and other sterile hymenial elements" absent; context generative hyphae 3-5 microns wide, thin-walled, colorless, with clamp connections, rarely branched, context skeletal hyphae 3-8.5 microns wide, thick-walled, colorless, without clamp connections, with rare branching, context binding hyphae 2-4 microns wide, thick-walled, colorless, much branched, branches often tapering; tramal hyphae similar, (Gilbertson)

Spore Deposit:
rusty brown (Gilbertson)