Soft, pliable, rubbery bright yellow shelf with crinkly gills. No hairs on cap, velvety surface, spore print not determined. Growing on wet conifer log populated with slime molds and dried Auricula.

Added last two photos to show forked gills and staining on the 1st, and the lack of any indication of an attachment to the wood on the 2nd. The fruit body peeled away like modeling clay – the foamy kind that comes from the craft store and had imprints of the wood on it.

If you are seeing this for the first time, you can read about it in old manuals like Arora MDM under the name Paxillus…,

Update 10/27/2011 this fungus continued to fruit all summer; added photos from August 19.

Species Lists


Forked gills of large shelf at maturity;
note brown staining from handling
forked and cross-linked gills
No stem or strong attachment to log – it just peels off.
August 19, 2011 update
August 19, 2011 update
rusty brown spores
sometimes with olive cast

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

= Observer’s choice
= Current consensus


Add Comment
Thanks Roy!
By: Nathan Wilson (nathan)
2012-01-19 22:45:06 CST (-0500)

I’ll work on getting it cleaned up tomorrow.

Yes, Pseudomerulius
By: Roy Halling (royh)
2012-01-19 16:20:36 CST (-0500)

W. Jülich in Persoonia 10:330, 1979, erected the genus Pseudomerulius based on Merulius aureus Fr. as type. He states that the spores are yellowish brown. Only 2 spp. in the genus according to Ginns (cited in my last comment below).

So Pseudomerulius curtisii it is?
By: Nathan Wilson (nathan)
2012-01-19 14:39:06 CST (-0500)

I’m pretty sure we’re still only talking about one taxon and it sounds like based on Roy’s excellent notes that Pseudomerulius curtisii is the current name and Tapinella corrugata, Paxillus corrugatus and Paxillus curtisii are synonyms. My only hesitation is Irene’s comment about Pseudomerulius having white spores. According to MycoBank Pseudomerulius aureus is the type for Pseudomerulius which several sites report as having white to yellow spores. I’m certainly comfortable with the idea of a genus having a range of spore colors, I just want to make sure we’re all on the same page before I go through another round of changes on the site.

Synonymy from
By: Roy Halling (royh)
2012-01-19 14:02:51 CST (-0500)

(1) O. Miller & D. Farr. 1975. An Index to the Common Fungi of North America (Synonymy and Common Names) Bibilotheca Mcyologica 44: 1-206.
(2) J. Ginns & M.N.L. Lefebvre. 1993. Lignicolous Corticioid Fungi (Basidiomycota) of North America, Systematics, Distribution, and Ecology. Mycologia Memoirs 19: 1-247.
NB: In this latter, Jim Ginns indicates he studied Atkinson’s TYPE of Paxillus corrugatus deposited at Cornell.

You’re welcome, Walt!

By: Michael Wood (mykoweb)
2012-01-19 12:24:57 CST (-0500)

I was wondering about the synonomy of P. curtisii and P. corrugatus after photographing one in the GSMNP last summer. I could not find any info in the sources I had. Where did the synonomy information come from?

Thanks Roy.
By: walt sturgeon (Mycowalt)
2012-01-19 11:31:46 CST (-0500)
By: Roy Halling (royh)
2012-01-19 10:43:09 CST (-0500)

Now I know why you asked for my thoughts on the taxonomy under my Obs = 86480. In the paper by Binder et al (2010. Mycologia 102:865-880), the results of a 6 gene phylogeny show Pseudomerulius near the base of the Boletales clade clearly separate from Tapinella. Both are members of the suborder Tapinellinae. Brown rotting corticioids are appearing basal to pileate-stipitate ectomycorrhizal forming boletes in several lineages. Paxillus panuoides is a Tapinella. Paxillus corrugatus is a later synonym of Paxillus curtisii. This latter is now considered a Pseudomerulius.
The specimen noted in my Obs 86480, I called a Meiorganum for awhile, only because the collection came from Australia, and the type, Meiorganum neocaledonicum, came from offshore on New Caledonia. I didn’t think any more of it, and sent it to Manfred Binder for sequencing. In hindsight, I should have paid heed that I was collecting in a disturbed forest containing introduced pines.

Old e mail is relevant.
By: walt sturgeon (Mycowalt)
2012-01-17 14:08:39 CST (-0500)

From G. Kibby

Well, I tracked down the Redhead et al. paper and found that they don’t mention Meiorganum at all but they do discuss the problem of Tapinella versus Pseudomerulius and I quote their words below:

“For example, we do not consider Paxillus curtisii Berkeley, which is often placed in the same section as T. panuoides when both are treated in Paxillus (e.g. Singer, 1975), to be congeneric with the latter as had been earlier suggested (Ginns, 1976, p.122). Rather, it is intermediate between Leucogyrophana Pouzar in the Coniophoraceae (cf. Ginns, 1978) and Tapinella, and belongs in a separate genus, Pseudomerulius Julich [Pseudomerulius curtisii (Berkeley) comb. nov, basionym Paxillus curtisii Berkeley in Berkeley & Curtis, Ann. & Mag. Nat. Hist. 12(Ser. 2): 423, 1853]. Paxillus, Tapinella, Pseudomerulius and Leucogyrophana form an evolutionary series exhibiting different levels of hymenial organisation or pileus and stipe formation.”

So it would seems that they consider Pseudomerulius to be even more extreme in its morphology (and more like Coniophora) than Tapinella. I imagine someone has done the DNA by now.

Not a Pseudomerulius…
By: Nathan Wilson (nathan)
2012-01-16 17:08:36 CST (-0500)

So the one thing that seems clear from this discussion is that there are two mixed up taxon names. One is for what has been historically called Tapinella corrugata in the eastern US. All of the observations I see on the site at the moment appear to be consistent with this species concept. Index Fungorum and MycoBank both consider this name valid. I believe Irene’s argument would suggest that we call this Tapinella curtisii which has not as far as I can tell been published. Calling it either Paxillus curtisii or Pseudomerulius curtisii seems wrong to me, so for now I’m going to stick with Tapinella currugata. Pseudomerulius curtisii remains a valid name for a distinct taxon.

Thanks, Doug!
By: Irene Andersson (irenea)
2011-06-14 03:26:34 CDT (-0400)

I think you were right!!

I finally found Berkeley’s original description of Paxillus curtisii (in “Annals and Magazine of Natural History 12: 423”). It’s done exactly like Atkinsons did with corrugata, mentioning the resemblance with Tapinella(Paxillus) panuoides, but with brighter colours, orange and more plicate gills, and clearly smaller spores. Pilei 1-3 inches broad, mostly reniform, somtimes elongated.

This means that the non-original description in MycoBank probably refers to something else.. and that curtisii probably should be the preferred name (described 1853) before corrugata (1900), whether it’s Meiorganum, Pseudomerulius or Tapinella.

Thanks everyone!
By: Martin Livezey (MLivezey)
2011-06-13 20:42:05 CDT (-0400)

Samples are available if anyone cares to take a look.

By: Douglas Smith (douglas)
2011-06-13 15:47:41 CDT (-0400)

The state of things here can be changed by anyone, you can set it back as needed. I think I went through this a while ago on an obs. from upstate NY of mine. I saw that Tapinella curtsii could be the best id there, and that Pseudomerulius curtisii was the best name. And I believe as part of that a source that said T. curtsii was a synonym for T. corrugata. But in 5 mins of searching here, I didn’t see that again.

I also didn’t see much detail in good descriptions for either T. corrugata or P. curtisii, so I’m not completely sure they are different or not, or what to say really…

It would be good to get someone to look for the mushroom again in the type location to get a good photo and… (yadda-yadda the normal noise on how we should try to clear up confusions again and again…). At least for P. curtisii, since there seem to be lots of photos of T. corrugata from the eastern US here, and people agree they should be called T. corrugata it seems.

The only place
By: Irene Andersson (irenea)
2011-06-13 11:56:43 CDT (-0400)

where I can find Tapinella corrugata and Pseudomerulius curtisii claimed to be synonyms, is here at MO…

It’s quite clear to me that Tapinella and Pseudomerulius are closely related. This Tapinella corrugata actually looks like an intermediate between these genera, with pilei like Tapinella panuoides, but with more merulioid “gills” than in other Tapinella species. That, and the gills becoming orange, is how Atkinson told it apart from Tapinella panuoides. He also described the spores as yellowish (spore print olive yellow), ellipsoid, 3 × 1.5-2 microns.

I still have doubts about it being a synonym to Pseudomerulius curtisii, given how it was described: “effused-reflexed with a narrow pileus, or completely resupinate, sometimes with imbricate, dimidiate pilei up to 2 × 1 × 0.5 cm” (spores 3.5-4 × 1.5-2 µm).
It was described from Hawaii, as both Paxillus curtisii and Paxillus corrugatus, but it does NOT mean that they are synonyms, only that someone happened to label it as corrugatus – back in 1981.

Irene: Tapinella to Pseudomerulius is a mystery to me.
By: walt sturgeon (Mycowalt)
2011-06-13 10:20:31 CDT (-0400)

This brown spored entity I learned as Paxillus corrugatus which is a synonym of Tapinella corrugata. In Bessette & Roody’s North American Boletes it is Meiorganum curtisii. This species is deprecated on MO, reference: Douglas Smith
Status: Deprecated
Name: Meiorganum curtisii
Author: (Berk.) Singer, Garcia & Gomez
Citation: Beih. Nova Hedwigia 98: 63 (1990)
Deprecated Synonym(s): Paxillus curtisii Berk., Paxillus corrugatus

Note P.corrugatus synonym referenced above.

From the USDA:Pseudomerulius curtisii (Berk.) Redhead & Ginns 1985 (Basidiomycetes, Boletales)

≡ Paxillus curtisii Berk. 1853

≡Meiorganum curtisii (Berk.) Singer, Garcia & Gomez 1990 Note: A homonym exists for this name.

Distribution: Eastern North America.

Substrate: On dead wood.

This has rusty brown spores
By: Martin Livezey (MLivezey)
2011-06-13 09:23:52 CDT (-0400)

(rusty-brown w/ faint greenish cast). I am mistaken about the synonymy on index fungorum. Synonymy is claimed on MO only for T. corrugata and P. curtisii.

By: Irene Andersson (irenea)
2011-06-13 02:32:25 CDT (-0400)

Tapinella has rusty brown spores, Pseudomerulius has white spores..

I compared
By: Irene Andersson (irenea)
2011-06-13 02:04:53 CDT (-0400)

Tapinella panuoides and corrugata, and corrugata seems to have much brighter colours, like this one.

But where can I find information about Tapinella corrugata and Pseudomerulius curtisii being the same..??

This doesn’t look like the description of the latter. Just take a look at it here:

A typical Pseudomerulius is resupinate with a narrow pileus, not pleurotoid like Tapinella (and this).

By: Matt Sherman (Shermanii)
2011-06-04 16:00:40 CDT (-0400)

neat find

Compare with
By: walt sturgeon (Mycowalt)
2011-06-04 14:57:54 CDT (-0400)

Tapinella panuoides and decide if they are really 2 species.

Noah and Walt you are both right
By: Martin Livezey (MLivezey)
2011-06-04 14:50:12 CDT (-0400)

name is deprecated to Pseudomerulius curtisii in 1985. Gill shots added. Index Fungorum lists this in Boletales – I am surprised at that.

Created: 2011-06-04 12:49:30 CDT (-0400)
Last modified: 2012-07-27 13:31:52 CDT (-0400)
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