Ganoderma lobatum

Scientific name:  Ganoderma lobatum (Cooke) G.F. Atk.
Derivation of name:   Ganoderma means having a " shiny
or lustrous skin"; lobos means "lobed" referring to the
lobes found on this species.
Synonymy:  Scindalma lobatum (Cooke) Kuntze.,
Polyporus lobatus Schwein.
Common names: Western Penn Mushroom Club
lists this species as the "soft artist's conk."
Phylum:   Basidiomycota
Order:   Polyporales
Family:   Ganodermataceae
Occurrence on wood substrate: Saprobic, solitary to
grouped on hardwood logs and stumps; annual
found year-round.
Dimensions:  Caps up to 20 cm wide.
Upper surface: Gray to grayish-black or brown, often
concentrically furrowed or zoned; white margin present
when growing; surface crusty, finely cracked and
wrinkled; dull. The surface can be "crunched-in" or
cracked using just the pressure of a thumb or fingernail
(Figure 11). Contrast this to the harder surface of G.
applanatum (which resembles G. lobatum) that
cannot be cracked or punctured with thumb pressure.
Flesh of cap: Dark brown to cinnamon-brown, woody.
Pore surface: Whitish, can be drawn on like that of
the artist's conk, Ganoderma applanatum; 4-6 pores
per mm.
Edibility: Inedible.
Comments:  Ganoderma lobatum, although an annual
species, typically produces a new cap (conk) each year from
the wood directly beneath the dead and decomposing
fruit body of the prior year. If the new conk grows up
into the prior year's decaying fruit body, it may fuse into
the previous year's growth. Because the older, dead fruit
bodies persist for several years, a given specimen may
appear perennial when in reality it is a series of stacked caps.
Compare this manner of growth to that of a true perennial
species such as Ganoderma applanatum which produces
a new layer of tubes on the same conk each year with the
entire conk remaining alive.

More information at MushroomExpert.com

Figure 1. Ganoderma lobatum on a redbud tree (Cercis
canadensis). Photo © Cecily Franklin.


Figure 2. The pore surface is white on young and mature
specimens but darkens with age.
Photo © Cecily Franklin.

Figure 3. Underneath the grayish cap surface (cuticle), the cap
flesh (context) is brown.
Photo © Cecily Franklin.

Figure 4. Ganoderma lobatum may have a short, stubby stipe
(pseudostipe) or even a a long stipe if fruiting from buried wood.
Photo © Cara A. Coulter.

Figure 5. Ganoderma lobatum on a display table at the 2019
NEMF foray in Lock Haven, PA. This was the first time I saw
a specimen identified as Ganoderma lobatum.
Photo © Gary Emberger.

Figure 6. Underside of the specimen in Figure 5. From all the
handling this specimen received, the white pore surface is
quite discolored.
Photo © Gary Emberger.

Figure 7. Overlapping shelves (conks) of Ganoderma lobatum.
Note the concentrically furrowed or zoned caps.
Photo © Maricel Patino.

Figure 8. The growing edge (margin) is often white.
Photo © Maricel Patino.

Figure 9. This photograph is a good example of the manner in
which Ganoderma lobatum produces a new cap (conk) from
the wood directly beneath the dead and decomposing
prior year's fruit body. Here, the new, larger cap is directly
under the smaller, somewhat decrepit-looking previous year's
cap resulting in the stacked appearance of the specimen.
Photo © Emily Happell Williams.


Figure 10. As in Figure 9, this is another example of a younger
cap forming under the decomposing previous year's cap.
Photo © Andrew Loyd.

Figure 11. The thumb pressure test. The cap cuticle of this
specimen was fractured (at the two places outlined in red) by
applying just the pressure of a thumb. A healthy specimen of
Ganoderma applanatum could be fractured in this manner.
Photo © Matt Schink.