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When: 2021-09-27

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

Who: Eric (eozkan)

Specimen available

Collected these mushrooms from the identical site as my recent OBS 470062 in order to confirm habitat as being dominated by Spruce trees. Photos indicate discovery location at the side of a rural road beneath a small Sitka Spruce flanked by two small Blue Spruces. Mushrooms were densest directly beneath the center tree. Second location photo shows the nearest pine to the discovery site, a distant mature White Pine with a number of mature spruce trees in between it and the discovery site. This collection appears to be a Suillus associated with spruce rather than typical pine. Would appreciate help with identification.


Directly beneath Sitka spruce.
Directly beneath Sitka spruce.
Discovery site, X’s mark mushrooms.
Nearest pine to the discovery site.

Proposed Names

57% (1)
Recognized by sight
84% (1)
Based on chemical features: The derived full-length ITS sequence Blasts to numerous accessions of European S. granulatus and also matches the sequence of my own collection of this taxon made in Lithuania, obs 379806

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= Observer’s choice
= Current consensus


Add Comment
Thanks Igor, this is interesting. I’ll see if I can dig up anything on…
By: Eric (eozkan)
2021-12-15 12:38:59 AEDT (+1100)

this mushroom and its association with firs and spruce.

By: I. G. Safonov (IGSafonov)
2021-12-15 09:19:21 AEDT (+1100)

Mycorrhizal associations of Suillus are well-established and highly evolved. Most taxa became fastidious specialists associated with a single tree species or a particular genus in Pinaceae (e.g., Larix and Pseudotsuga). On the other hand, other suillus can grow with a broader range of hosts, but trees belong to a particular group [e.g., “hard pines” (2-3 needles)]. Yet, there are documented or case-specific exceptions. For example, S. subaureus grows with oaks and sometimes hemlock (personal observation). I came across S. americanus, S. spraguei and S. weaverae in a grove of hemlock, but these taxa are known to grow only under P. strobus. I also collected S. luteus on my property growing under 3 white pines, but luteus?? is reported to be an exclusive “hard pine” associate by Nguyen et al. (2016).
The significance of your collection is that it’s not associated with Pinus. I don’t know if S. granulatus is capable of establishing itself with Picea or Abies in Europe. Is this something you could look into?

Our old friend S. granulatus! What is the significance of this Igor? How…
By: Eric (eozkan)
2021-12-15 08:12:46 AEDT (+1100)

…unusual is it to find this mushroom apparently associated with Spruce as opposed to Pine? As you know, every other example I’ve collected in my area thus far (at least 4 distinct locales) has had Red Pine in close association.

Thank you so much for your continuing efforts in sorting out these interesting fungi! In terms of postings, I’m currently quite backlogged but I don’t think I have any other Suillus to post from this season.

Thanks, Igor! I already have these drying and will gladly send them along to you.
By: Eric (eozkan)
2021-09-28 10:38:57 AEST (+1000)
Nice ecological documentation
By: I. G. Safonov (IGSafonov)
2021-09-28 08:47:36 AEST (+1000)

Thanks, Eric for the extra details. The pictures are very convincing!
I draw my info regarding the host-symbiont relationships from the global Suillus phylogenetic study by Nguyen et al. (2016). Spruces and firs are not mentioned as hosts in this paper.
The mysterious mycorrhizal association aside, I think you may have here a European or Western NA species imported with the planted tree(s).
Let’s get this critter sequenced! :-)