Sporocarp
Fruiting body perennial,woody, typically sessile, 6-60 cm broad, 5-10 cm thick, fan-shaped to slightly convex, rarely hoof-like, usually solitary; margin rounded early, becoming narrowed at maturity; surface a hard crust, dull grey, grey-brown to brown, irregular, often furrowed, nodulose and zonate, frequently dusted with brown spores. Flesh up to 6.0 cm thick, brown, tough, corky, blackening in KOH.
Pores
Pores 4-6 per mm, white, quickly bruising brown when injured, fading to pale yellowish-buff when dried; tubes multi-seried, 4-13 mm long, brown, each layer separated by a thin layer of tissue; tubes and pores blackening in KOH.
Spores
Spores 6-9.5 x 5.7 µm, broadly elliptical, blunt at the distal end, thick-walled, ornamented with minute spines; spores brown in deposit.
Habitat
Solitary or in small groups on downed logs of both hardwood and conifers, also on living trees; especially common on Umbellularia californica (California bay).
Edibility
Inedible, woody.
Comments
Our best known shelf fungus, Ganoderma applanatum is distinguished from other woody polypores by a dull grey-brown, bumpy, usually zonate cap, often powdered brown from released spores, and a white pore surface which instantly darkens when injured. The latter feature makes it a favorite of artists which use the smooth white surface as a canvas. Like a number of perennial woody conks, the age of a fruiting body can be roughly determined by sectioning and counting the tube layers. Related fungi include Ganoderma tsugae, uncommon in our area, with a shiny red/brown to mahogany brown cap and pores that do not bruise and Fomitopsis pinicola with a reddish-brown cap margin and pores that bruise slowly pale yellowish-buff. One other Ganoderma that occurs in California is Ganoderma brownii. According to Gilbertson & Ryvarden, it is similar to Ganoderma applanatum but differs in having larger spores and a yellow pore surface.
References
Arora, D. (1986). Mushrooms Demystified. Ten Speed Press: Berkeley, CA. 959 p.
Bernicchia, A. (2005). Polyporaceae s.l. (Fungi Europaei). Edizioni Candusso: Alassio, Italy. 807p.
Bessette, A.E., Smith, D.G. & Bessette, A.R. (2021). Polypores and Similar Fungi of Eastern and Central North America. University of Texas Press: Austin, TX. 430 p.
Breitenbach, J. & Kränzlin, F. (1986). Fungi of Switzerland. Volume 2: Non-Gilled Fungi. Verlag Mykologia: Luzern, Switzerland. 412 p.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Ellis, M.B. & Ellis, J.P. (1990). Fungi without Gills (Hymenomycetes and Gasteromycetes). Chapman and Hall: London, England. 329 p.
Gilbertson, R.L. & Ryvarden, L. (1986). North American Polypores, vol. 1. Fungiflora: Oslo, Norway. 433p. (PDF)
Ginns, J. (2017). Polypores of British Columbia (Fungi: Basidiomycota). British Columbia: Victoria, BC. 260 p. (PDF)
Lindsey, J.P. & Gilbertson, R.L. (1978). Basidiomycetes that Decay Aspen in North America. J. Cramer: Vaduz. 406p.
Overholts, L.O. (1953). The Polyporaceae of the United States, Alaska, and Canada. University of Michigan Press: Ann Arbor, MN. 466p. (PDF)
Other Descriptions and Photos
Main Photo
- Nathan Wilson: Artist Conk (CP)
- Michael Wood: Ganoderma applanatum (CP)
- Michael Wood: Ganoderma applanatum (CP)
- Michael Wood: Ganoderma applanatum (CP)
- Michael Wood: Artist conk given to Dr. Harry Thiers, 1986 (CP)
- Michael Wood: Artist conk given to Dr. Tom Volk, 2001. Art by Louise Freedman. (CP)
- Common Tree Diseases of British Columbia: Ganoderma applanatum (D & CP)
- Robert Rich: Ganoderma applanatum (D & CP)
- Mushroom Observer: Ganoderma applanatum (CP)
- Arora (1986): p. 576 (D & P)
- Arora (1991): p. 194 (D & CP)
- Gilberton & Ryvarden (1986): p. 290 (I), p. 291 (D)
- Jordan: p. 106 (D & CP)
- Lincoff: p. 460 (D), plate 518 (CP)
- Miller: sp. 319 (D)
(D=Description; I=Illustration; P=Photo; CP=Color Photo)
