Name: Gymnopilus penetrans (Fr.) Murrill
Most Confident Observations:
Version: 8
Previous Version 

First person to use this name on MO: Nathan Wilson
Editors: walt sturgeon, Erlon Bailey


Rank: Species

Status: Accepted

Name: Gymnopilus penetrans

ICN Identifier: missing

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Author: (Fr.) Murrill

Citation: Mycologia 4(5): 254 (1912)

Deprecated Synonyms: Flammula croceolamellata Pilát


Domain: Eukarya

Kingdom: Fungi

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Agaricales

Family: Hymenogastraceae

Genus: Gymnopilus

Show Subtaxa

Notes on Taxonomy: [Edit]

HABITAT: On dead coniferous wood, usually on pine.
DISTRIBUTION: Throughout temperate North America; Cuba and Jamaica; also in Europe.
ILLUSTRATIONS: Cooke, Brit. Fungi pi. 447 {487) (as Agaricus sapineus); Fries, Ic. Hymen.
pi. 118, f.2. .
EXSICCATI: Ellis, N. Am. Fungi 906 (as Agaricus sapineus).

Brief Description: [See More | Edit]

Characteristics in brief: Fruitbodies medium- sized, pileus covered with white to greyish-white velum when young, the velum disappears soon, colour yellow at margin, towards centre yellow-ochre, ochre-brown, orange- brown to rusty brown, surface smooth but finely innately rusty ochre to rusty brown fibrillose-striped, in some fruit- bodies with disrupted covering forming fine, appressed, fib- rillose scales, lamellae rather pale yellow when young, stipe pale ochre, brownish to rusty brown, covered with remnants of velum which are white and tomentose-fibrillose, base white tomentose with white mycelial cords, context pale yellow in pileus, taste distinctly bitter; spores medium-sized, mostly 7.2–8.8 × 4.4–5.2 μm, ellipsoid to amygdaliform-ellipsoid with slight suprahilar depression, ornamentation moderate- ly developed, verrucose to rugulose-verrucose, cheilocys- tidia variable: cylindrical, narrowly fusiform-cylindrical, narrowly lageniform-fusiform to lageniform, apex mostly with globose head 4–7 μm in diam., upper layer of pileus cuticle visible (scalp) as a loose net of hyphae or hyphal cords forming the fibrillose to scaly pileus covering, cells cylindrical, narrow: 3–10(–12) μm in diam. Growing as a saprophyte on dead wood of conifers and deciduous trees, from the lowlands to the mountains, common.

Description: 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 hemis- phaerical-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 hy- grophanous, 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 fib- rillose-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, seg- mentiform to slightly ventricose but sometimes also trian- gular, 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 irreg- ularly 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, to- mentose 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, sor- did 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.

Spores (6.8–)7.2–8.8(–9.5) × (4.2–)4.4–5.2(–5.6) μm, E = 1.45–1.82, Q = 1.65, ellipsoid to amygdaliform-ellipsoid both in side and face view, in side view with slight suprahi- lar depression, rusty yellow in KOH, wall darker, rusty brown, ornamentation moderately developed, verrucose to rugulose-verrucose, without suprahilar disc, protoplasm of mature spores distinctly red-brown in Melzer’s reagent (dextrinoid), wall remaining bright yellow to yellow-rusty, young or immature spores without this reaction. Basidia 24–28 × 6–7 μm, 4(2)-spored, broadly cylindrical with me- dian constriction and attenuated basal part. Basidiolae re- sembling basidia, smaller. Cheilocystidia rarely intermixed with basidia at edge, 24–48 × 5.5–9 μm, variable in shape: cylindrical, narrowly fusiform-cylindrical, narrowly lageni- form-fusiform to lageniform, apex with more or less pro- nounced globose head 4–7 μm in diam. but sometimes not capitate, rarely with slightly thickened and rusty yellow wall of the head, mostly thin-walled, hyaline, at places filled with homogeneous rusty brown content. Pleurocystidia rarely present, lageniform with globose head or utriform, mostly absent. Lamellar trama regular, hyphae 3–14 μm broad, cells cylindrical or slightly fusiform inflated, hya- line. Velum (from cortina between pileus margin and stipe) made up of cords of parallel to slightly interwoven hyphae which are hyaline, thin-walled, not incrusted, cells cylindri- cal, 2.5–6.5 μm broad, with clamps at all septa. Pileus cuti- cle (section) a thin cutis of densely arranged hyphae 3–7 μm broad, cells cylindrical, rusty brown incrusted, covered with nests of parallel to interwoven hyphae forming the scales which are more intensely coloured, rusty brown, of cylin- drical to narrowly fusiform cells 4–10 μm broad, whole cu- ticle sometimes covered with a thin layer of less coarsely incrusted hyphae of velum (only slightly dotted), scalp sur- face covered by a loose net of hyphae or hyphal cords form- ing the fibrillose to scaly pileus covering, cells cylindrical, 3–10(–12) μm broad, medium to coarsely rusty brown in- crusted (“zebra” to “panther” pattern), special terminal ele- ments or pileocystidia not present. Stipe cuticle a cutis of parallel cylindrical hyphae 2–6 μm broad, with yellow- brown wall and scarce incrustations or with cellular pig- ment, covered with a thin layer of parallel to interwoven, hyaline velum hyphae 2–5 μm broad, loosely arranged, rarely with yellow-brown incrustations, caulocystidia and special terminal elements not observed.

Fructification: Rarely – in second half of June, whole July, August, first half of December; commonly – September-November, most frequently – September-Octo- ber (CR).

E c o l o g y : In the Czech Republic, Gymnopilus pene- trans is found as a saprophyte on dead wood of conifers but also deciduous trees, especially on fallen trunks, stumps, twigs, wood debris, wood chips etc., rarely also on wood used by man, e.g. in hot-beds. The species grows on wood in all stages of decay except for soft, almost completely de- cayed wood. Most finds are from Abies alba, Picea abies, Pinus sylvestris and Fagus sylvatica; one from Betula. Gymnopilus penetrans grows in almost all types of forests, both natural and man-made, in purely coniferous stands as well as in mixed forests, but also in clearings (on heaps of wood chips or on roots), parks and places with wood debris. It often occurs in groups or fascicles of tens or hundreds of fruitbodies. The species can be found from the lowlands up to the highest parts of mountains in the CR.
Concerning the spectrum of host trees, I know also finds from Salix and Pinus nigra (see Collections studied). Høi- land (1990, under name G. sapineus) mentions also Junipe- rus, Alnus, Quercus, Populus tremula and Fraxinus from Norway (in all cases only 1–3 finds). One find is from Em- petrum. He writes that the species prefers the most frequent substrate at hand, which is Pinus and Picea in regions with coniferous forests and Betula in regions with deciduous forests. This agrees with my observations from the Czech Republic except for Quercus and Carpinus forests in the warmest regions where the species does not grow on wood of these hosts but on introduced Picea or Pinus. However, G. penetrans is common on Fagus in Fagus forests or mixed forests with Fagus. Krisai-Greilhuber (1992: 139, under the name G. hybridus) mentions finds on Fagus, Quercus and Carpinus from deciduous forests in the vicinity of Wien (Austria). Orton (1993: 64) writes that the species (under name G. hybridus) is one of the few agarics found com- monly on decaying Quercus wood in some oakwood areas of Great Britain. Generally, G. penetrans is a species with a broad spectrum of hosts but clearly preferring conifers. From deciduous trees, the species prefers dominant forest- forming species like Fagus, Betula and Quercus (data from Central and Western Europe and Scandinavia).

Distribution: Gymnopilus penetrans is a common species in all parts of the Czech Republic, especially in re- gions with a high percentage of coniferous or mixed forests.

The species is common in most European countries. In Scandinavia, it is found up to the subarctic/subalpine zone (Ryman 1992).


Descriptions: [Create]


Add Comment
By: Rocky Houghtby
2013-12-11 17:47:17 CST (-0500)

It is worth mentioning that in 2005 Jan Holec published a paper titled:

In which he acknowledges Fries’ concept of A. sapineus but determines that Maire’s (and thusly
Kühner ‘s and Romagnesi’s) concept is a different mushroom. The epithet is preserved by selecting Maire’s Gymnopilus as the type. Holec found distinct microscopic differences between G. penetrans(fries) and G. sapineus(Maire).

Long story short, G. sapineus and G. penetrans are not synonyms, but G. sapineus does need to be relabeled with Maire as the sanctioning author.
In Holecs paper he names it as such-

Gymnopilus sapineus (Fr.: Fr.) Maire
sensu Kühner et Romagnesi (1953), Moser (1983), Lud- wig (2000, 2001), Breitenbach et Kränzlin (2000); non G.
sapineus sensu Fries (1821), Høiland (1990).

As to wether or not NA G. sapineus matches EU G. sapineus… No one has worked on that yet.

By: Rocky Houghtby
2013-12-11 16:55:27 CST (-0500)

Penetrans was published first. It doesn’t matter how Mike Kuo interpreted the literature. If this is to be deprecated, penetrans would be the appropriate taxon.

Now, that Guzman study… Guzman didn’t find any micromorphological differences between her penetrans and sapineus specimens? Look at the differences in micro between the two in Hesler. The spores are in completely different ranges! This begs the question- was Guzman comparing G. sapineus sensu Murrill or sensu Fries, because they are not the same mushroom. For the time being I strongly feel that North American material should not be synonymized with G. penetrans.

By: walt sturgeon (Mycowalt)
2013-11-27 00:41:32 CST (-0500)

Current Name:
Gymnopilus penetrans (Fr.) Murrill, Mycologia 4(5): 254 (1912)


Agaricus liquiritiae subsp. sapineus (Fr.) Pers., Mycol. eur. (Erlanga) 3: 184 (1828)
Agaricus penetrans Fr., Observ. mycol. (Havniae) 1: 23 (1815)
Agaricus penetrans var. australis Berk., J. Linn. Soc., Bot. 13: 158 (1872)
Agaricus penetrans Fr., Observ. mycol. (Havniae) 1: 23 (1815) var. penetrans
Dryophila penetrans (Fr.) Quél., Enchir. fung. (Paris): 71 (1886)
Flammula croceolamellata Pilát, Bull. trimest. Soc. mycol. Fr. 54(3-4): 251 (1939) 1938

Flammula penetrans (Fr.) Quél., Enchir. fung. (Paris): 71 (1886)
Flammula penetrans var. australis (Berk.) Sacc., Syll. fung. (Abellini) 5: 823 (1887)
Flammula penetrans var. madagascariensis Henn.
Flammula penetrans (Fr.) Quél., Enchir. fung. (Paris): 71 (1886) var. penetrans

Fulvidula penetrans (Fr.) Singer, Revue Mycol., Paris 2(6): 239 (1937)

Gymnopilus penetrans (Fr.) Murrill, Mycologia 4(5): 254 (1912) var. penetrans
Naucoria penetrans (Fr.) Henn., (1898)

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