Observation 116464: Caloboletus marshii D. Arora, C.F. Schwarz & J.L. Frank

When: 2012-11-03

Collection location: Stebbins Cold Canyon Reserve, Solano Co., California, USA [Click for map]

Who: Byrain

Specimen available

Growing under mixed hardwoods, Pinus sabiniana is around too. The taste was bitter. Observations 4606 & 70861 are similar.

Spore range = 11 – 13 × 4 – 5 μ
Average spore = 12.1 × 4.85 μ
Q range = 2.2 – 2.75
Average Q = 2.5
20 spores measured.


Spores, 1000x, mounted in KOH
Spores, 1000x, mounted in KOH, 1μ divisions

Proposed Names

-28% (1)
Recognized by sight: Except the stem is not very red…
11% (2)
Recognized by sight

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Thanks again.
By: Byrain
2012-11-12 10:43:21 MST (-0700)

That explanation is very helpful, Boletaceae is a tricky group for me. :)

Other observations
By: Christian (Christian Schwarz)
2012-11-11 21:35:31 MST (-0700)

That you mentioned have either a bit more red in the stipe (70861) or a different stature and cap texture/cracking pattern (4606), and both are from locations where there is unlikely to be live oaks – both the other species are conifer associates. But yes, they do look similar in many respects, and are part of the same group (bitter boletes).

Dry day
By: Byrain
2012-11-11 21:08:43 MST (-0700)

This was the only mushroom I found on the trail, it was in a dark part of the forest and towards the end of the day so my pics turned out pretty dark and green… Good thing tripods and gimp exist. :)

Do you think observations 4606 & 70861 are B. “marshii” too? They certainly still look similar to me.

No problem
By: Christian (Christian Schwarz)
2012-11-11 20:47:32 MST (-0700)

Good find and pictures, and nice work.

Thanks Christian
By: Byrain
2012-11-11 20:42:41 MST (-0700)

That seems like a much better fit.

Created: 2012-11-11 20:24:46 MST (-0700)
Last modified: 2014-10-26 07:25:47 MST (-0700)
Viewed: 96 times, last viewed: 2017-11-11 20:13:51 MST (-0700)
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