A new Suillus (for me)
Received a mushroom identification request this week for a fungus growing on the ground under a "spruce" by Harrigan Centennial Hall. The fungus in the photo I was sent was pretty clearly a Suilllus because it had a veil that was cream colored, lacked glandular dots on the stem and wasn't associated with Larch. The character that jumped out the most from the photo was the brown bruising of the pores, definitely not something I had seen around here.
I tried to run through the key to Suilllus on the Pacific Northwest Key Council site, but the photo lacked information about several key features used in the key (viscidness was the first).
Once I had it in hand the following were the characters that I used to help me identify ( or misidentify) it:
Cinnamon brown cap with very fine fibrous sort of look, it was not viscid, but had a few needles stuck to the cap
Cap turning dark with KOH
Pores yellow, bruising red brown
Veil didn't form a distinctive ring, more of a zone on the stem, there were a few fragments on the cap rim
Stem solid, slowly and indistinctly turning blue-green
Associated with Douglas Fir
I used Mushroom Matchmaker: Mushrooms of the Pacific Northwest (handy synoptic key) as my texts were at home and I was anxious to try the program out again. It pretty quickly took me to Suillus lakei (Yeah, a name!), reading the description, it seemed to fit pretty well and there was enough variation in the photos available on Mushroom expert that I decided that it was a positive identification.
I looked at a few similar species (in my mind) e. g. Suillus caerulescens and dismissed it because of the lack of a distinctive color reaction in the stem of the fungus in question.
I started feeling a bit less certain when I looked at the descriptions and photos in Mushrooms Demystified (Arora) and Mushrooms of the Pacific Northwest (Trudell and Ammirati). For one the lakei were all pretty red and/or fibrillose looking and what reinforced the sense of disquiet was the lack of discussion in the descriptions of species that I thought were similar. Why didn't neither book's discussion of lakei talk about how to distinguish it from caerulescens? What was I missing?
It seems like I was perhaps not paying enough attention to the overall color the cap of lakei (reddish) vs cinnamon brown (caerulescens) that is distinctive enough to rarely cause confusion and the more extensive fibrils found on lakei .
This is a brief synopsis of the small group of Suillus species included in Arora and Boletes in the PNW) that have ring zones, yellow pores that stain brown that are found with Douglas Fir.
S. ponderosa: has a viscid, bright yellow veil and a smooth cap
S. lakei: fibrillose with reddish brown to brick red or pinkish fibrils (occasionally tawny). Viscid when wet, stalk weakly turning blue or green when cut
S. caerulescens: dry, whitish veil, cap smooth or fibrillose, viscid when wet, stalk turning blue or green when cut, sometimes slowly.
I found myself leaning back toward S. caerulescens at this point, the lack of fibrils is starting to seem like a problem. Still a bit uncomfortable with the identification, I turned to another book (A. H. Smiths and H. Thiers monograph on North American Suillus) and was relieved to finally see the difference between these two species addressed.
" It (caerulescens) differs from S. lakei in having a distinct change to blue in the stipe and in having numberous large latifciferous ducts in the context of the cap. ..."
Well, now I have to make a judgment call; are the fibrils more important than the blue reaction? I did pick another sample today and cut it open fairly quickly after picking. It did turn blue, not abundantly, but more so than previously. No real joy yet.
Guess I'll have to look for lactciferous ducts next.
