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When: 2021-08-02

Collection location: Interlochen, Michigan, USA [Click for map]

Who: Eric (eozkan)

No specimen available

Collected this all-yellow waxcap growing from a well-rotted log in a mixed woodland. Would appreciate help with more specific name if possible.


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= Observer’s choice
= Current consensus


Add Comment
I think the spore pictures are helpful.
By: Dave W (Dave W)
2021-08-12 10:11:28 PDT (-0700)

Of course it would be good to be able to estimate L and W. But, by using a piece of paper with an edge folded to the approximate size of the widths, it appears to me the Q=L/W are in the 1.4-1.7 range, the seeming expectation for G. nitidus. Q for Chrysomphalina chrysophylla spores can be expected to exceed 2.0 (for at least some seen in profile). Seeing the prominently displayed apiculi provides a reason to believe the spores seen in these photos are indeed positioned favorably to get a read on Q. Also, photos I have found online of C. chrysophylla spores do not show prominent apiculi. So, I’d say the spore photos appear to offer some support to the G. nitidus proposal. Wiki lists two other species of Chrysomphalina besides C. chrysophylla. I have found no information on either of these.

I’ve added a couple photomicrographs from the spore prints I took from these…
By: Eric (eozkan)
2021-08-12 09:47:45 PDT (-0700)

mushrooms to the observation for you experten to look at. Apologies for the poor quality but I’m no microscopist…these are just simple micrographs, sample in water, ordinary light, mag is 400X, photo taken through the scope lens with my iPhone. Still, they show the basic morphology of the spores. Hopefully this is helpful.

perceived need for epitype
By: Steve (Lokness)
2021-08-11 21:27:02 PDT (-0700)

Great comments here and with most fungi I would wholeheartedly agree. Since there is not a single observation on iNat nor MO for SC., it might be a trick to get a valid epitype? Reading in Hesler and Smith they briefly in a confused statement mention that type is from SC – which Joe did such a great job of finding – BUT, Hesler and Smith offered no further observations for South Carolina! They list the observations in all the other states – but nothing further from SC. ……..Maybe GW could be used to explain the lack of observations in SC today, but that wouldn’t explain the lack of observations by scientist for the period 1849 – 1963 (year Hesler and Smith was published).

As mentioned below the area where the original type was found is now likely under water. An epitype might have to come from NC? I guess this would be a several year effort and a try for a sequence on mushroom Joe found should at least be tried first. That might be a long shot though.

The fruit bodies seen here…
By: Dave W (Dave W)
2021-08-11 19:56:47 PDT (-0700)

are larger than what I remember IDing as G. nitidus here in NE PA (once). The habitat was moss-covered humus-enriched forest soil. Also saw this species name applied once at a NEMF foray.

Spore morphology for G. nitidus differs from that of Chrysomphalina chrysophylla (the latter with longer spores having larger Q=L/W). There seems to be little readily available information on the other two species of Chrysomphalina.

Given that 100+ year old material may fail to yield to any sequencing attempt, I think in at least some cases (like maybe G. nitidus) there will be a perceived need for an epitype. In such a situation a collection made in the same (or at least nearby) location as the type specimen would be preferable… if not a downright requirement.

Gloioxanthomyces nitidus
By: Steve (Lokness)
2021-08-10 07:27:47 PDT (-0700)

Good chance the type mushroom location is now under water. Another reason type in this particular instance type may not be of much value. It was collected near Santee Canal which was later abandoned and much of the area flooded by a very large lake.

Jean Lodge looked and didn’t like G. nitidus and suggested Chrysomphalina. Gets more interesting all the time.

Type for Gloioxanthomyces nitidus
By: Steve (Lokness)
2021-08-09 10:57:02 PDT (-0700)

Thanks for information on type for this guy. Very informative! A couple of comments;

1) As important as Type is, this is another instance where I wonder how valuable it really is. Case by case. A look at crowd sourcing from iNat and MO shows not a single example of this species in South Carolina – nor anywhere as far south as South Carolina for that matter. The huge majority of the observations are much further north on up into Canada. So even if there is a valid type it looks to be on the extreme edge of this mushrooms range. If there is a wee bit of differences whether in physical characteristics or DNA across the range you may NOT be looking at a very representative example of the species when looking at type.
2) What can we hope to get for DNA out of a mushroom harvested in 1849? Not saying you can’t just saying the odds are slipping on a mushroom from over 170 years ago.
3) While type is of course dried and decreased some in size I suspect, when compared to the mushroom here, the type mushroom looks pretty small. More how I imagined it. 1/2" to 1" and those I suspect were measurements before it was dried. ……….Also in type description is mentioned ….“viscid”.

Type collection @ FH
By: Joseph D. Cohen (Joe Cohen)
2021-08-09 10:17:57 PDT (-0700)

The holotype of Gloioxanthomyces nitidus (Hygrophorus nitidus), see, is actually in Harvard’s Farlow Herbarium (FH). See, e.g.:

Hesler & Smith are wrong in referring to the type as being ‘at Kew’.

“often on rotten wood”
By: Steve (Lokness)
2021-08-09 08:47:43 PDT (-0700)

Thanks Dave! Very informative. Another of the mushrooms from the Hygrophoraceae that have a mysterious “type”.

Hesler and Smith says type is from South Carolina but then they go on to say a collection of Ellis at the New York Botanical Garden ………agree with the type at Kew? Huh? What the heck does that mean? That the South Carolina type ended up in Kew? I rather doubt it so there may be a conflict as to which even is the type here? No name is associated with the South Carolina type – so who would ever try to run this down?

Champignons du Quebec says of G. nitidus…
By: Dave W (Dave W)
2021-08-09 01:29:24 PDT (-0700)

“often on rotten wood” (via Google translate).

On wood?
By: Steve (Lokness)
2021-08-08 15:27:31 PDT (-0700)

I sure can’t use the attachment to wood as a case for Humidicutis as those are not growing on wood either. It could be that the G. nitidus does occasionally show up growing on well rotted wood – but I have no experience with the species at all so maybe someone else can speak to that. Hygrocybe cantharellus does show up occasionally on wood – so there is that examnple?

Please send me one and we’ll get the DNA to tell us what it is for sure.

Steve, regarding growth from wood: I added a photo of one of the dried stems…
By: Eric (eozkan)
2021-08-08 14:43:49 PDT (-0700)

…that seems to clearly show direct attachment of this mushroom’s stem to wood. I will be happy to forward a dried sample of this collection to you. These guys are pretty insubstantial once dried but I can send a nice cap w/stem and the stem sample attached to wood from the added photo.

Thanks for your interest Steve! Per your suggestion I tested some dried specimens…
By: Eric (eozkan)
2021-08-08 13:31:07 PDT (-0700)

for odor and didn’t detect anything remarkable. Although I thought these particular specimens appeared to be growing from the rotting wood as shown, it’s possible they were growing from the soil BENEATH the wood. I should have checked that at the time but didn’t. I certainly collected a number of these guys from soil as well (see obs 463816).

Gloioxanthomyces nitidus
By: Steve (Lokness)
2021-08-08 11:03:42 PDT (-0700)

Two votes for G. nitidus! I may have to update my concept of the G. nitidus.

It still seems wrong to me for the following reasons; 1) way too big. 2) growing on wood. 3) does not look viscid.

Boertmann suggest G. nitidus is same species as H. vitellina which is a tiny viscid guy growing on “moist soil”. Likely there are more than one species under the G. nitidus umbrella? Washington State is listed in Hesler and Smith as having G. nitidus but that is it for the west. My guess is that the Washington State mushroom from mountains is perhaps an entirely different species?

Great find and extremely well done pictures for IDing.

Maybe Humidictis?
By: Steve (Lokness)
2021-08-06 18:06:00 PDT (-0700)

Does it have an odor while drying?

Growing out of wood has me puzzled? Xeromphalina – but too big?