Observation 34923: Pluteus phaeocyanopus Minnis & Sundb.

When: 2010-03-18

Collection location: Bon Tempe Reservoir, Marin Co., California, USA [Click for map]

Who: Ron Pastorino (Ronpast)

Specimen available

These were growing on a very mossy log in mixed woods of Live oak, fir and some pine.
The caps were somewhat radially rugulose/wrinkled and up to 4.0 cm across.
The pale stipe was greenish streaked but did not appear to discolor.
The pink spores were subglobose, ~ 7.0-8.0 X 6.0-7.0 microns, with an off center dimple or apical pore.
The cap cuticle seemed cellular lacking cystidia. (see photo)
The gills did have some clavate cystidia(two photos).
No strong odor that I could detect.
Nothing seems to match up so far.

Species Lists



Proposed Names

-31% (4)
Recognized by sight: A common Pluteus with bluing base in our area
Used references: http://mushroomhobby.com/...
-25% (3)
Recognized by sight: Thanks to the excellent presentation, my keys lead directly to this species (cyanopus, blue on the stipe; nanus, not blue..)
68% (7)
Eye3 Eyes3
Recognized by sight: A better match with the shape of the cystidia and size of the mushroom..

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
The micro drawings match pretty well
By: Dimitar Bojantchev (dimitar)
2010-03-22 12:38:24 PDT (-0700)

When comparing the drawings from the paper that Irene provided below – page 97, to the structures shown on my page, they match quite in aspect and size. Also on my page you can see that darker intercellular pigment – not as “bad” as what you see in Leptonia, but still visible..

It seems to me that P. phaeocyanopus is unlikely because…
By: Christian (Christian Schwarz)
2010-03-22 10:15:04 PDT (-0700)

that species is supposedly distinguished by more narrowly lageniform cystidia (these appear utriform to broadly lageniform), and is supposed to have with brown intracystidial content – these look more or less hyaline to me, but I am used to looking at Leptonia where the pigment forms very dark, discrete blobs.

I agree, but…
By: Dimitar Bojantchev (dimitar)
2010-03-21 23:46:15 PDT (-0700)

there are general things about this description that bothered me. I’ll discuss more on MT, otherwise I think this id makes sense now.

Pluteus phaeocyanopus looks pretty good
By: Ron Pastorino (Ronpast)
2010-03-20 14:37:25 PDT (-0700)

to me also. See North American Fungi 5(1) Pluteus section Celloluderma in the U.S.A. Minnis & Sundberg pp44-46,97. http://www.pnwfungi.org/ The spore size also matches better and it is a local species apparently growing on Live oak. We’ll see how long this one lasts.

We seem to need an Intermediary here..
By: Ron Pastorino (Ronpast)
2010-03-20 10:47:23 PDT (-0700)
With regard to the Minnis and Sundberg reference, the description for Pluteus cyanopus is on pages 30,31, and 86. Page 49 contains a statement that ‘..it is unclear if (pluteus nanus is) found in the U.S.A.", and they don’t deal with it. Another confusing element is the “bluish gray at the base” part of the description. I guess “greenish” is a kind of bluish gray but I’m sticking to greenish streaked throughout the stipe and it also shows up in the dried material.
You guys figure this one out and let me know… (at the end).
By: Dimitar Bojantchev (dimitar)
2010-03-20 10:18:14 PDT (-0700)

Irene, why are you doing to me — arguing and disagreeing — dumping new sources, as if I have all day long to read on Pluteus…

Anyway, I plugged the name P. nanus after an email exchange with Else Vellinga on Feb 14, 2008. I have the email I sent and I know she responded, but I lost that communication.

The microstructures for P. cyanopus as captured in Flora Agaricina Neerlandica do not agree well with this collection, or mine.

As far as the bluing or graying, not sure which anymore, I will have to recall exactly what was said in that email, but I’d like to hear what Else has to say now. The easiest thing is to change the name, but getting there may not be…

As to the new paper from Minnis & Sundberg, just a quick scan does not reveal to me any micro-morphology for either cyanopus or nanus that I can use to draw a quick conclusion, but I haven’t had the chance to read it – it probably makes deeper points.

But I shouldn’t as I have other things to do today. You guys figure this one out, I’m checking out…

For those who want to dig deeper into Pluteology
By: Irene Andersson (irenea)
2010-03-20 10:01:02 PDT (-0700)

and this particular section:

Nice ob, done the way it should be done!!
By: Dimitar Bojantchev (dimitar)
2010-03-20 09:09:22 PDT (-0700)

Ron, this is a beautiful observation and you should be commended for it. Capturing the pileipellis layer is critical when dealing with Pluteus and many other Genera. The hymeniform layer formed of pyriform to broadly clavate cells fits nicely with Pluteus nanus, a rather common Pluteus species in our area. The bluing base is quite typical too. Show it to Else, she likes to mess around with Pluteus too and I passed my observation by her as a sanity check some time ago…

Hmm, you’re right, Debbie
By: Irene Andersson (irenea)
2010-03-20 08:48:57 PDT (-0700)

Kuo, Moser, and the old description i Saccardo’s Sylloge Fungorum says a smaller spore size (and a smaller mushroom too).
According to Funga Nordica, the range of spore size in cyanopus is (7-)7.5-9(-10) x (5.5-)6-6.5(-7.5) μm.
The keys there are mainly based on Vellinga and Flora Agaricina Neerlandica.

Could it be more than one species that’s interpreted as cyanopus..?
Let’s hope that Else takes a look at this obs.

the spores don’t seem to match with cyanopus.
By: Debbie Viess (amanitarita)
2010-03-20 08:08:30 PDT (-0700)

at least for the spore size given on Kuo’s Pluteus webpage…

Is there anything
By: Irene Andersson (irenea)
2010-03-20 02:09:57 PDT (-0700)

that speaks against Pluteus cyanopus?

Created: 2010-03-19 20:06:18 PDT (-0700)
Last modified: 2015-01-15 11:59:49 PST (-0800)
Viewed: 726 times, last viewed: 2019-01-13 10:00:33 PST (-0800)
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