Observation 169310: Gymnopilus penetrans (Fr.) Murrill
When: 2014-07-08
Collection location: Perry, Maine, USA [Click for map]
No herbarium specimen
0 Sequences

Cap up to 2.5 cm, orange brown becoming yellow brown, finely hairy. Gills yellow spotting orange brown. Partial veil. Whitish mycelium at base of stem. On decayed stump in mixed woods. Orange brown spore deposit. KOH on cap dark red. Heavy rains on 7/5.

Proposed Names

-14% (2)
Recognized by sight
36% (2)
Recognized by sight: as likely as obs 19001, 32675,60562,83538,15722,83903…..this is what the field guides call G. sapineus and what 100 + MO users call it—many of them with less information, eg. spore print and chemical tests
Used references: Kuo, M. (2007, February). Gymnopilus sapineus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/gymnopilus_sapineus.html and Mushrooms of Northeast NA, George Barron and http://www.mykoweb.com/CAF/species/Gymnopilus_sapineus.html
Based on chemical features: KOH on cap dark red
46% (2)
Recognized by sight
Used references: Holec

Please login to propose your own names and vote on existing names.

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
“highly colored…”
By: Richard Kneal (bloodworm)
2014-07-25 18:39:59 PDT (-0700)

im not really sure what that means…but,
Holec did a brilliant job of seperating the two species based on morphology…
but, even he states that he thinks the two species may be the same and are most likely in a very closely related group.
but, he has respect for the authors…
which is the most important aspect of his paper.
he adheres to idea that what we perceive is more important than what we cannot.

so…there are 2 options.
G. penetrans or G. sapineus group.

By: Rocky Houghtby
2014-07-25 10:59:05 PDT (-0700)

penetrans is at least (for the time being) an apparent valid name for North America, it is not necessarily a good label for this observation. My concept of penetrans is a smaller, more highly colored mushroom.

By: Richard Kneal (bloodworm)
2014-07-25 07:49:54 PDT (-0700)

“G. penetrans

D e s c r i p t i o n : Fruitbodies growing singly, in groups
or fascicles. Pileus (10–)20–80(–100) mm, surface strongly
variable in colour and appearance depending on age and
weather conditions, when young hemisphaerical to hemisphaerical-
conical with inflexed to involute margin, then
convex to convex-conical, sometimes with low broad umbo,
finally plano-convex to slightly concave, dry, mat, not hygrophanous,
not translucently striate, in very young fruit-bodies rather dark, brown (6D7),
grey-brown, whole surface covered with white to greyish-white tomentose-arachnoid velum which connects pileus margin and stipe, later present
at pileus margin only, soon completely disappearing, pileus
at maturity pale yellow (4A6) to yellow, towards centre
darker, yellow-ochre, ochre-brown, orange-brown to rusty
brown, often with rusty spots, in old fruitbodies sometimes
homogeneously rusty to ochre-brown, surface smooth but
almost always finely innately rusty ochre to rusty brown fibrillose-
striped, in some fruitbodies with disrupted covering
forming fine, appressed, fibrillose scales (fibrillose and scaly
pilei often present in various fruitbodies of the same fascicle).
Lamellae crowded, L = 40–60, l = 1–7, 3–8 mm high, segmentiform
to slightly ventricose but sometimes also triangular,
near stipe emarginate and decurrent with a small
tooth or broadly adnate to slightly decurrent, at first pale
yellow (even in this state sometimes rusty spotted – under
dry conditions), then yellow-ochre, yellow-rusty, orange
ochre-rusty, finally to deep rusty brown, often rusty spotted,
edge concolorous or somewhat paler, even or slightly irregularly
serrulate, surface changing rusty brown when
bruised. Stipe 20–80(–100) × 3–10(–12) mm, cylindrical or
slightly gradually thickened towards base, being slightly
bulbous in some cases, sometimes eccentric, connected with
stipe with a whitish velum leaving a disrupted, whitish, tomentose
annular zone, soon disappearing, upper part pale
yellow, finely pruinose, towards base pale ochre, brownish
to rusty brown but covered with remnants of velum which
are white and tomentose-fibrillose, base white tomentose
with white mycelial cords. Context pale yellow in pileus, sordid
ochre when moist, in stipe yellow, pale yellow-rusty to
pale rusty brown. Taste immediately distinctly bitter. Smell
acidulous-fungoid (like Suillus bovinus) or fruity-spicy.

G. sapineus

D e s c r i p t i o n : Fruitbodies growing singly, in groups
or fascicles. Pileus 1.5–6.5 cm, convex, plano-convex, finally
applanate, sometimes with low broad umbo, dry, mat,
not hygrophanous, not translucently striate, margin deep
yellow to yellow-ochre, towards centre darker, deep ochrerusty,
yellow-brown to rusty brown, sometimes also with
slight orange tinge, surface finely fibrillose-tomentose, tomentose
to tomentose-scaly, scales fine, appressed to slightly
upraised. Lamellae medium crowded, L = 40–60, l = 1–5,
3–6 mm high, ventricose, near stipe emarginate and decurrent
with a small tooth, at first mat yellow, then deep yellow,
finally rusty, sometimes slightly rusty spotted, edge even,
pale yellow. Stipe 30–60 × 3–7(–10) mm, either slender and
gradually thickened downwards or rather robust and cylindrical,
without traces of velum, upper part yellow, towards
base deep yellow-ochre, ochre-rusty to rusty brown, surface
finely pale yellow to yellow fibrillose-tomentose. Context
typically deep yellow in pileus (like lamellae), but sometimes
also pale yellow; yellow-rusty in stipe. Taste moderately
bitter to bitter. Smell rather distinct, earthy-raphanoid,
musty, like Cortinarius traganus, in lamellae sometimes
slightly iodoform-like.

D i s c u s s i o n : Gymnopilus penetrans is a common but
very variable species. It is typical by its medium sized fruitbodies
growing often in large groups or fascicles, yellow,
yellow-ochre, yellow-orange to rusty brown colours, pale
yellow colour of young lamellae, white to greyish-white
velum on young pilei which disappears soon, stipe covered
with white tomentose-fibrillose velum remnants, pale yellow
context of pileus, distinctly bitter taste, medium sized
spores with moderately developed ornamentation and above
all by narrow hyphae in the upper layer of the pileus cuticle
(3–10(–12) μm in diam.).

The differences between Gymnopilus penetrans and G.
sapineus sensu Kühner et Romagnesi (1953) etc. are thoroughly
discussed under G. sapineus. In brief, G. penetrans
has a paler pileus without a tomentose surface, narrower hyphae
of the pileus cuticle and produces fruitbodies mostly in
autumn (September – November: situation in the CR). See
also the papers by Clémençon (2002, 2003)."



By: Rocky Houghtby
2014-07-25 07:10:29 PDT (-0700)

In the sense of Fries was determined to be a synonym for penetrans. The epithet sapineus has been reserved and now belongs to a species described by Marie. Murrill based his concept of F. sapineus on Fries’ A. sapineus. North American species that have been previously labelled as sapineus are labelled incorrectly. Your collection isn’t a particularly good match for Fries’ or Murrill’s sapineus. Michael’s page for sapineus can be used to describe at least five of Hesler’s North American Gymnopilus species, right down to the microscopy. If you want to find out what these actually are, I recommend you send them to one of several mycologists in NA actively working on this genus.

Created: 2014-07-09 05:31:42 PDT (-0700)
Last modified: 2014-07-26 08:16:13 PDT (-0700)
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