Observation 64661: Pluteus Fr.

When: 2011-03-22

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

Who: Ron Pastorino (Ronpast)

Specimen available

This lone specimen was growing on a piece of old wood with predominately Doug Fir in the area.
The cap was 1.9 cm across.
The stem was greenish and became more brownish with handling.
The spore print was a dark pink and the spores were ~ 6.8-7.4 X 6.2-7.2 microns.
There seemed to be some Cheilocystidia(see photos).


Cheilocystidia in Congo Red @ 1000X
Cheilocystidia in Congo Red @ 1000X
Cheilocystidia in Congo Red @ 1000X
Cap surface in 3%KOH @ 1000X
Cap surface in 3%KOH @ 1000X

Proposed Names

42% (5)
Recognized by sight
-2% (2)
Recognized by sight: I don’t know if the micro details are a match, but macroscopically it looks about right, especially the bluish tones in the stem.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Thanks Matt and Doug for the comments and
By: Ron Pastorino (Ronpast)
2011-03-24 14:21:53 MDT (-0600)

yes Doug, I did mean #52975. However, I still am leaning toward P. romellii because, as I stated in the original description, the stem was initially distinctly “greenish” or a kind of yellow-green color that was not too evident in the photos. I handled it too much and dropped it in the dirt setting up the photos. You can see traces of that color in the photos, especially near the apex.
However, I just noticed in MD that Pluteus lutescens aka P. nanus var. lutescens has a pale yellow stem.(?) Guess I need to do more reading.

Wrong obs. there…
By: Douglas Smith (douglas)
2011-03-24 12:57:41 MDT (-0600)

I think you mean 52975… but check out these obs. first:


I think I would lean towards P. nanus on this. P. romellii really needs the chrome yellow stipe.

Added a couple of micro shots of the cap surface
By: Ron Pastorino (Ronpast)
2011-03-24 12:35:46 MDT (-0600)

and Doug, they are looking fairly close to your MO #52795 of Pluteus romellii.
I have also previously posted this species from the same general area without the more extensive microscope work. The cap on this one seemed a little darker brown than many of the other observations for this species, but probably not the most important feature.

By: Matt Sherman (Shermanii)
2011-03-24 12:27:44 MDT (-0600)

Nice microscopy.
What stain did you use for the cystidia?


Thanks for the update.

Need to look at cap surface…
By: Douglas Smith (douglas)
2011-03-24 08:34:06 MDT (-0600)

Need to look at the cap surface here. Although I am pretty sure it is a hymeniderm. But species can be split on the surface elements, are they uniform, random, pigments are inter-cellular or not. I went a little Pluteus crazy this last season, and you can look at some of my posts from Europe here to get examples.

Created: 2011-03-23 22:10:13 MDT (-0600)
Last modified: 2011-03-25 13:52:29 MDT (-0600)
Viewed: 129 times, last viewed: 2017-06-09 06:59:58 MDT (-0600)
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