|Major Groups > Polypores > Ganoderma tsugae|
by Michael Kuo
This beautiful mushroom is closely related to Ganoderma lucidum and is virtually indistinguishable from that species on the basis of physical features alone. However, Ganoderma tsugae is partial to conifers—especially hemlocks and firs—while Ganoderma lucidum is found on the wood of hardwoods. Additionally, it has whitish, rather than brownish flesh. Otherwise it is recognized, like Ganoderma lucidum, by its varnished cap and stem.
The similar Ganoderma oregonense, labeled "doubtfully distinct" from Ganoderma tsugae by Gilbertson and Ryvarden (1986), is a conifer lover of the Pacific Northwest and New Mexico; it is reported to have larger spores (10–16 x 7.5–9 µm) and a much larger fruiting body (up to one meter across!) that only rarely develops a stem.
The taxonomy of Ganoderma, especially within the lucidum species complex, is pretty much up for grabs at the moment, and many recent studies have been published (e.g. Cao et al. 2012, Wang et al. 2012, Yang & Feng 2013, Wang et al. 2014, Zhou et al. 2014, Hapuarachchi et al. 2015, Richter et al. 2015). Results among these studies are sometimes contradictory—and some of the GenBank sequences being used in the studies may represent misidentifications—so the wisest course at the moment seems to be to let the dust settle and use the hardwoods-lucidum/conifers-tsugae equation until there is a different mycological consensus.
Ecology: Parasitic on living conifers (especially eastern hemlock and western hemlocks) and saprobic on the deadwood of conifers; producing a white butt rot of the heartwood; growing alone, scattered, or gregariously; annual; widely distributed in North America where hemlocks occur, and occasionally reported from the Southwest. The illustrated and described collections are from Michigan, Ohio, Québec, and Oregon.
Cap: 4–24 cm; at first irregularly knobby or elongated, but by maturity more or less fan- or kidney-shaped; with a shiny, varnished surface often roughly arranged into lumpy "zones"; bald; dark red to orangish red or reddish brown when mature; when young often with zones of bright yellow and white toward the margin.
Pore Surface: Whitish, becoming dingy reddish brown in age; usually bruising brown; with 4–6 tiny (nearly invisible to the naked eye) circular pores per mm; tubes to 2 cm deep.
Stem: Sometimes absent, but more commonly present; 3–14 cm long; up to 3 cm thick; equal or irregular; varnished and colored like the cap; often distinctively angled away from one side of the cap.
Flesh: Whitish when fresh, becoming brownish with age; fairly soft when young, but soon tough.
Chemical Reactions: KOH instantly black on flesh and tubes.
Spore Print: Brown.
Microscopic Features: Spores 8–13 x 5–7 µm (see note above); more or less ellipsoid, sometimes with a truncated end; under oil immersion appearing double-walled, with a row of "pillars" between the walls. Setae and cystidia absent. Hyphal system dimitic. Terminal cells on cap surface clavate; 7.5–12.5 µm wide; thick-walled; golden in KOH.
REFERENCES: Murrill, 1902. (Saccardo, 1905; Overholts, 1953; Smith, Smith & Weber, 1981; Gilbertson & Ryvarden, 1986; Phillips, 1991/2005; Lincoff, 1992; Roody, 2003; McNeil, 2006; Kuo & Methven, 2014 tsugae.) Herb. Kuo 09110402, 07271201, 09301301.
Thanks to Laurence Boomer for collecting, documenting, and preserving some of the illustrated and described specimens.
This website contains no information about the edibility or toxicity of mushrooms.
Cite this page as:
Kuo, M. (2016, August). Ganoderma tsugae. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/ganoderma_tsugae.html