Summary:
Features include small size, a whitish to pinkish brown grooved cap, adnate whitish to cap-colored gills, a tough brown to blackish stem that is pinkish to ochraceous at top, a strong odor of putrid water, and growth on individual conifer needles. |Petersen(29) calls the eastern North American collections subspecies transatlanticus, and say that they differ from the European collections in 1) having shorter, slenderer fruitbodies, 2) smaller spores, pleurocystidia, and basidia, 3) cheilocystidia infrequent, smaller and less differentiated, and 4) fruiting on fallen Picea, Abies, and Tsuga needles. It remains to be seen whether Pacific Northwest collections represent the true Paragymnopus perforans or other related species. |Petersen(29) described three related species (Gymnopus bulliformis, G. fragillior, and G. glabrosipes) from the Pacific Northwest in 2016, albeit from dried material without DNA evidence, but does not list Gymnopus perforans (or Paragymnopus perforans) from that region. All three of these species had been deposited in herbaria as Gymnopus perforans (and two of them also as Gymnopus androsaceus). |Paragymnopus perforans (as Gymnopus) of North America was separated from European Paragymnopus perforans by base pair divergence of only 1.65%, so the North American material as a new subspecies transatlanticus, rather than as a different species. This subspecies was recombined by Oliveira(1) as Paragymnopus perforans subsp. transatlanticus (R.H. Petersen) J.S. Oliveira. |Also to be considered is Paragymnopus sublaccatus. Paragymnopus sublaccatus (as Gymnopus) was reasonably separated from Paragymnopus perforans considered as a whole (base pair divergence 2.3%) although the authors say that 3% is often used as an expectation for different species. But if they include only North American Paragymnopus perforans, Paragymnopus sublaccatus does not separate as clearly (and nor does Paragymnopus sequoiae (as Gymnopus)). After an interesting discussion about peripheral speciation, their conclusion is "G. sequoiae and G. sublaccatus appear to be offshoots of one branch within North American G. perforans. In this latter case, genetic isolation may be in part geographical and in part ecological but it is clear that some genetic separation has occurred." (Petersen(29) with Latin names italicized).

Gills:
"adnate, fairly crowded", interveined; whitish, (Lincoff), broadly adnate, 14-17 reaching stem, 3-7 subgills between each pair of gills, broad; "light beige to flesh-colored"; edges smooth, (Breitenbach), rather distant; cap-colored, (Moser), "often appearing to be attached to a collarium", close to subdistant, subgills present in moderate numbers, interveined; whitish, (Bessette)

Stem:
2-3cm long and about 0.1cm wide, tough; "brown turning blackish, pinkish at the top"; velvety, (Lincoff), 1.3-3cm x 0.08-0.12cm, cylindric, hollow, elastic; black-brown, top paler to whitish; "tomentose from small tufts of hairs", (Breitenbach), 3-6cm x 0.05-0.1cm, shining black except at the pale top, (Hansen), ochraceous at top, otherwise black-brownish; "fine small hairs visible under microscope", (Moser), whitish to yellowish at top, "purplish brown to reddish brown overall, nearly black at the base"; scurfy, (Bessette)

Odor:
strong of putrid water, with a hint of garlic, (Lincoff), cabbage to garlic-like, mild, (Breitenbach), "unpleasant, not really garlic-like", (Moser), "strongly of stagnant water and/or with a hint of garlic", (Bessette), unpleasant, like rotting cabbage or broccoli, (Trudell), fetid, like rotten cabbage, (Petersen for European description), negligible to fetid (occasionally weakly alliaceous), (Petersen for North American material)

Taste:
strong of putrid water, with a hint of garlic, (Lincoff), cabbage to garlic-like, mild, (Breitenbach), "strongly of stagnant water and/or with a hint of garlic", (Bessette), mildly unpleasant, often tardily alliaceous, (Petersen for European description), moderately alliaceous (Petersen for North American material)

Microscopic spores:
spores 5.5-6 x 3 microns, "lanceolate, smooth", (Lincoff), spores 5.7-8 x 2.8-4 microns, elliptic - tear-shaped, smooth, iodine-negative, colorless, with droplets; basidia 4-spored, 27-40 x 4.5-6.5 microns, narrowly clavate, with basal clamp connection; pleurocystidia and cheilocystidia 30-40 x 3-5 microns, fusiform to narrowly clavate; cap cuticle "of +/- parallel, in part branched hyphae 2.5-3.5 microns across, with epimembranal brownish pigmentation, walls somewhat gelatinized, some septa with clamps", (Breitenbach), spores 5-8 x 3-3.5 microns, illustration looks more or less narrow elliptic, (Hansen), spores 5.5-6 x 3 microns, (Moser), spores 5-7 x 3-3.5 microns (Bessette)

Spore deposit:
white (Lincoff)

Notes:
Paragymnopus perforans has been found at least in WA (Ammirati). There are multiple collections from WA at the University of Washington and multiple collections from BC at the University of British Columbia. It has also been recorded from northeastern North America (NL, NS, QC, CT, NC, NY, and TN (Petersen(29) as subspecies transatlanticus)). It occurs in Europe including Denmark, Finland, Sweden, and Norway, (Hansen, L.), and Switzerland (Breitenbach). It also occurs in Russia (Petersen).

EDIBILITY

no value (Lincoff)

Synonyms and Alternate Names:
Gymnopus perforans (Hoffm.) Anton