Observation 51590: Cortinarius scaurus group

When: 2010-08-12

Collection location: Fraser Experimental Forest, Grand Co., Colorado, USA [Click for map]

Who: Ron Pastorino (Ronpast)

Specimen available

These look like they fit reasonably well with the descriptions.(of my original guess which was Cortinarius variicolor)
Caps were a little tacky and up to 5 cm across
KOH on the cap was slightly brown by my notes. (Literature indicates yellow)
KOH on other surfaces was neg.
The spores were ~ 9.8-11.0 X 6.0-6.9 microns and moderately rough.



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We defnitely should.
By: Dimitar Bojantchev (dimitar)
2010-08-31 22:11:14 PDT (-0700)

Thank you Ron, yes, getting a more complete picture of the Scaurus group in Western USA would always be of benefit. I am still processing your Spring Corts, so in a month I’ll talk to you about the Colorado collections — I want to organize them in a batch with some other material I plan to gather in the USA in Sep-Oct.


Thanks Dimitar,
By: Ron Pastorino (Ronpast)
2010-08-30 17:03:46 PDT (-0700)

C. scaurus does look like a better fit. Since Walt Sturgeon already has a “Cortinarius scaurus Group” observation on the site, I’ll go with that.
I do have a voucher so maybe someday we can “gene” it.

Cortinarius scaurus s.l.
By: Dimitar Bojantchev (dimitar)
2010-08-30 01:07:49 PDT (-0700)

Ron & Christian, you have correctly noticed the absence of strong yellow reaction on the context, which does present problems in applying the name variicolor. The overall stature of your specimen does remind members of Variecolores. But the spores of Variecolores group are very typical and not like these here — they tend to be longer, more narrowly amygdalyform and more inequilateral with even slight broad umbo, if that can be allied to spores.

I will have to put together a quick, high-level “Down to Section” key for Phlegmacium. Seeing people like you Ron who put quality obesrvations inspires me too to put some effort since if you deal with spores and macrochemical reactions that can be a powerful weapon in navigating these Phlegmacium Sections. Otherwise on a picture alone I couldn’t argue against Variecoclores at all.

You material seems to match quite well the Cortinarius scaurus group – to me it was typical from the first sight.

C. scaurus

Molecularly our Western American collections are very close to the European collections. We have one original species in that group Cortinarius montanus Kauffman

C. montanus

(accepted in Europe too, rightly or wrongly) and a number of species in the complex. For now I call them C. scaururs s.l., as I have no confidence that Cortinariology nomenclaturists and taxonomists to stand a chance to put some lasting names in that group. A lot of the debate is tied into doing forensic nomenclatural studies of what Fries meant and the people from that era. As a result every treatment of the group that I have seen so far is contradictory of previous treatments, including Bidaud et al 2009 and Moser’s work in 200-2002… I can go at great length, but I guess nobody will really care to read as the topic is very narrow…

Here you may need to open up your usage of iodine against some of thes ecollectoins, but its application is still quite limietd to that group and Purpurascentes where you see strong positive reactions.

When inspecting memebers of that group, look closely for water marks on the cap, particularly near the margin — they are very typical for these Sections and not present in Variecolores.


Thanks Christian but
By: Ron Pastorino (Ronpast)
2010-08-29 19:48:59 PDT (-0700)
there is still a good chance you were right. I had so many unnamed Cortinarius collections from Colorado, that after awhile one tends to force names on some of them. I’m still using 3%KOH and will go to 5% when I reorder. Maybe I’ll get some Cortinarius input on the Observation from the Balkans.
By: Christian (Christian Schwarz)
2010-08-29 17:24:35 PDT (-0700)

I guess “variicolor” should have been a clue to me.

I have had KOH rxns “fail” in cases where I thought they should have been sure. I have been using 5% lately instead of 3%.

Yes, spore size range – one of those great enigmas in the American mycological literature. It seems like it always fits SOMEONE’s size range concept, but rarely fits well with everyone’s reported values.

Thanks for keeping up on these Corts, Ron. I really enjoy these well-investigated observations.

You make some good points
By: Ron Pastorino (Ronpast)
2010-08-29 16:41:06 PDT (-0700)

However, the spore measurements in Roger Phillips’ Mushrooms of North America
are “8.5-11.6 X 5-6.5” microns. Some photos on the web show specimens with similar colors…it is called “variicolor”.
Can’t explain away the KOH…except it was late that night in Colorado and high altitudes tend to distort my color perceptions.

Spore size
By: Christian (Christian Schwarz)
2010-08-29 15:55:03 PDT (-0700)

Is shorter and wider than the range reported on MH, also the olive-yellow cap color (which appears neither the typical blue-purple nor as brighty yellow-brown as shown on MH) and differing KOH rxn seem to point against this determination.

For a further difference, look at the unruptured veil in the young specimens on MH – your youngest cap here doesn’t look like it ever had that very strong contiguous cortina

Created: 2010-08-29 15:42:48 PDT (-0700)
Last modified: 2010-08-31 09:52:39 PDT (-0700)
Viewed: 249 times, last viewed: 2018-12-16 17:59:15 PST (-0800)
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