Gilled Boletales

© Kit Scates Barnhart

Danny’s DNA Discoveries – gilled boletes of the PNW
by Danny Miller

Click here for my Pictorial Key to the gilled boletes

Introduction

Gilled boletes are in the order Boletales, more closely related to boletes than they are to most other gilled mushrooms which are found in the Agaricales. In fact, Phylloporus, the original gilled bolete, was one of the first mushrooms to teach mycologists that their morphologic classification system might not reflect their natural relationships. It was easy to assume that gilled and pored and spiny mushrooms belonged together with others like them. But when they first looked at the "gilled bolete", shown above, with its colour and stature exactly matching a number of boletes with a dark cap and bright yellow pores, and they turned it upside down, they found gills instead of pores. When the microscope was invented, they found it produced spores over twice as long as they are wide, just likes boletes do. Then they knew something was up and that mushrooms must have evolved back and forth between gills and pores more than once. As it turns out, it's not that big a change. Imagine pinching two gills together at regular intervals and you are creating pores. As as the DNA era has shown, convergent evolution (the same look coming about independently) is quite common. But Phylloporus was one the first clues.

Since then the microscope discovered that other mushrooms seemed to be bolete relatives, and DNA has confirmed it. You'll just have to learn how to recognize the various genera, but there is often a clue - gills that (especially near the stem) do something weird (after all, they didn't evolve with other gilled mushrooms) - either fork, wriggle, or become interveined almost to the point that they might start to look like pores where they attach to the stem.

I will also cover false truffles in the gilled bolete families.

abundant common uncommon rare - colour codes match my Pictorial Key and are my opinions and probably reflect my bias of living in W WA. Rare species may be locally common in certain places at certain times.

Summary of Interesting Results
Here are some of the newest, most interesting results of the study:

TBD

Phylloporus - click to expand
Boletaceae - These are very closely related to Xerocomus boletes, in fact it's not certain if they belong in Xerocomus or deserve their own genus. Their ITS sequences can be strange, with multiple copies of some portions, slightly modified, making them hard to align. Therefore, I am not certain as to their relationship to Xerocomus or each other in the ITS only trees I make.
Dark cap and bright yellow... gills, looking like so many true boletes with the same colour and stature.
Species mentioned: Phylloporus rhodoxantha, arenicola

Phylloporus rhodoxanthus EU - brown cap sometimes with red tones, decurrent gills that might stain blue. This species is reported from here, but even though I don't have EU DNA of this species to prove it one way or another, it is strongly suspected that it does not occur here but that reports represent one or more of the undescribed species below. We need more collections both here and from the EU to prove it, especially local collection with red in the cap to see what they really are.
Phylloporus arenicola OR - This locally described fall species is definitely here, described as having notched gills and no blue staining. We don't have a type sequence, but based on the description (but not the time of year), the best match so far might be #4, the only PNW species not to blue so far. I'm not sure, because it apparently has lookalikes we didn't know about.
The following genetic species have been sequenced from the west. Unfortunately they all have similar descriptions and can be quite variable.
Phylloporus PNW01 - fall, brown cap with fairly dark areas, decurrent, adnate or notched gills with a decurrent tooth, slow but distinct blue staining (in 5-10 minutes for one collection). It has been found in BC and WA so far.
Phylloporus PNW02 - fall, olive-brown cap, notched gills, no bluing noted even after cutting it in half. Stem may have red fibrils. Only known so far from CA and AZ, so not yet technically known from the PNW.
Phylloporus PNW03 - spring and fall, known from a sequence from WA (fall) ,OR (spring) and BC (fall), notched gills with a decurrent tooth (but perhaps decurrent), bluing distinctly.
Phylloporus PNW04 - spring, known from a single sequence from OR, notched gills and no bluing noted. Because of the lack of blue staining so far noted, perhaps this is the best match to Phylloporus arenicola so far, except that is supposed to be a fall species.
As you can see, we're far from working this out. To complicate things, ITS is crazy in this genus, with multiple copies of many parts of it that make sequences very hard to align and you have to stare at each pair of sequences for a while before it starts to make sense.

Phylloporus PNW01 © Yi-Min Wang

Phylloporus PNW02 from AZ © Terri Clements and Donna Fulton

Phylloporus PNW03 and PNW04 © Jonathan Frank

Hygrophoropsis - click to expand
Hygrophoropsidaceae - Commonly mistaken for a chanterelle by beginners, so therefore one of our "false chanterelles" with an orange cap and strongly decurrent bright orange forked gills. The caps on some species may be dark brown or even pale (almost white).
Species mentioned: Hygrophoropsis aurantiaca, rufa, pallida

Pale orange capped species
Hygrophoropsis aurantiaca EU - with a pale or bright orange cap and pale or bright orange gills, but the cap colour is usually uniform, whatever it is. Our local sequences are 2 bp and 2 indels and 1 ambiguous location different than EU sequences in ITS1, and ITS2 is identical. For now, I'm going to consider that our collections are the real thing.
Hygrophoropsis 'aurantiaca AK01' - also variably orange, but the caps don't seem to all be uniformly one colour. one collection in WA matches some AK and ENA sequences of this sister species.
Hygrophoropsis PNW05 - this species may be smaller, fuzzy capped, and overall bright orange. It was sequenced once near Seattle. We need more collections.
Hygrophoropsis pallida MA - notable for white gills. Also, a slightly fuzzy pale orange cap and orange stem. We have one OR sequence, but no east coast type area sequences to prove ours is the same species. For now, I'm assuming it is.
Hygrophoropsis PNW08 - similar to H. pallida, with creamsicle coloured gills, a fuzzy cap that is white with orange, and a bright orange stem. The only known sequences from anywhere in the world are one from WA and one from OR.

Hygrophorus aurantiaca © Stephen Russell, H. 'aurantiaca AK01' © Derek Hevel (from WA) and Christin Swearingen (2 images from AK)

Hygrophoropsis PNW05 © Danny Miller, H. pallida © Connor Dooley, H. PNW08 ©Yi-Min Wang (2 images) and Connor Dooley

Darker brown capped species
Hygrophoropsis PNW02 - resembling the EU Hygrophoropsis rufa, with red-orange-brown or chestnut colours on the cap and stem. The gills may be bright or pale orange. The spores average 5.5-6.5x3.5-4.5u. It has been found on a spruce twig and in sandy soil under pine. It has been sequenced from BC, WA and OR.
Hygrophoropsis PNW03 - our most common dark species has cold brown colours on the cap and a brown stem sometimes with orange tinges. It may have bright or pale orange gills. It can be robust (I don't know if PNW02 can be equally robust). The spores may be a bit larger, averaging 6-7x4-4.5u. It has also been found in BC, WA and OR. This species is sister to the EU Hygrophoropsis rufa, which has not been found in the PNW yet, even though PNW02 looks more like H. rufa.
Hygrophoropsis PNW06 - our one WA collection (not known from anywhere else) is yellow-brown, and most like PNW03.

Hygrophoropsis PNW02 © iNaturalist user reid02 (2 images) and Stephen Russell (2 images)

Hygrophoropsis PNW03 © Yi-Min Wang and Stephen Russell (2 images)

Hygrophoropsis PNW06 © Yi-Min Wang

Gomphidius and Chroogomphus - click to expand
Gomphidiaceae - Easily recognized fairly large, fleshy mushrooms with strongly decurrent gills and grey to black spores. Gomphidius are very slimy with white flesh that blackens. Chroogomphus are not slimy and have orange coloured flesh with water soluble pigments that can turn your urine red like beets.
Chroogomphus albipes CA and Chroogomphus loculatus OR are secotioids. Gomphogaster leucosarx is a trufflized mushroom in this family.
Species mentioned: Gomphidius glutinosus, largus, oregonensis, maculatus, pseudomaculatus, smithii, subroseus. Chroogomphus tomentosus, vinicolor subsp. californicus, ochraceus, pseudovinicolor, leptocystis, albipes, loculatus. Gomphogaster leucosarx.

Mushrooms in this family are oddly specific about which Suillus they parasitize. Since the EU generally has different Suillus species than we do, you'll notice that out of a dozen and a half or so species in the Gomphidiaceae found in the PNW, not a single species that wasn't described from here has been proven to be here (yet). I've never seen that in any other mushroom group.
Gomphidius
Gomphidius oregonensis OR -drab brown cap, bright yellow stem base, often clustered growth. Supposedly parasitic on Suillus caerulescens under Doug fir.
Gomphidius pseudomaculatus ID is a single collection from Idaho said lack the glutinous veil of G. oregonensis, but Idaho is dry and I'm not sure it's really a unique species. We need collections to find out.
Gomphidius cf glutinosus EU - perhaps a purplish cap and solitary growth. Bright yellow stem base. There are many reports of this in the PNW, but no genetic proof. We already suspect that eastern North America has an undescribed species and not the real thing, so we need local collections to find out what is really here. Whatever it is supposedly parasitizes Suillus ponderosus under Doug fir and perhaps a second species grows with coastal spruce.
Gomphidius largus ID may be a synonym of a very large G. glutinosus, so we need the type sequence or new very large collections.

Gomphidius oregonensis © Buck McAdoo,     G. cf glutinosus (what is it really?) © Michael Beug

Gomphidius subroseus OR - red cap fading to pinkish tan, bright yellow stem base, smaller size than G. oregonensis and usually a bit more brightly coloured even when faded. Parasitic on Suillus lakei under Doug fir. One sequence varies by 4 bp in ITS1 only, but I think there's only one species here.
Gomphidius PNW01 - known from one CO and one Vanc Island BC sequence, this resembles G. subroseus but is found away from Doug fir. The host bolete is not yet known, nor is its microscopic workup.
Gomphidius smithii OR - purple- to pinkish-tan cap, a little stem base yellowing. Difficult to differentiate from faded G. subroseus, its closest genetic relative. Even microscopically they are similar. Parasitic on Suillus lakei under Doug fir as well. BC and WA sequences differ by 2-4 bp from several AZ and UT sequences. I suspect our WA and BC collections are the real thing as it was described from western Oregon, and the UT and AZ collections might represent a Rocky Mountain variety.

G. subroseus © NAMA & the Field Museum of Natural History and Marty Kranabetter,     G. smithii © Danny Miller and Tajinder Sidhu

Gomphidius cf maculatus EU - drab cap, little stem yellowing. It's the only species said to lack any kind of fibrillose veil underneath the slime veil. With larch? We don't have an EU nor local sequences, but we have China and Quebec sequences that differ from each other by 2 bp and 3 ambiguities. Perhaps that's close enough to mean that they and we will have the real species, but we need local and EU sequences to find out.
Some of my ITS only trees show it is likely more closely related to Chroogomphus than to Gomphidius. At least a couple of papers show it inside Gomphidius with weak support. I am assuming it belongs in Gomphidius, but I thought I would point out that it would be nice to have a multi-gene study confirm that it isn't outside of both genera.

Gomphidius cf maculatus © Kit Scates Barnhart

Gomphogaster leucosarx ID - a blackening secotioid (almost a false truffle) probably more related to Gomphidius than Chroogomphus. No photo nor DNA yet to see if it deserves its own genus. It may not.

Chroogomphus
Chroogomphus tomentosus WA - an orange woolly dry capped species, often mistaken for a chanterelle by beginners. Parasitic on 'Boletus' mirabilis under hemlock.
Chroogomphus loculatus OR - this misshapen secotioid's type sequence is identical to all of our C. tomentosus ITS sequences, so it may only be a secotioid variety.
Chroogomphus leptocystis BC - a very similar, sister species perhaps with some grey in the cap, perhaps best differentiated microscopically. We only have 1 purported sequence of this from BC, but it sequences sister to C. tomentosus like it should, so it's probably identified correctly. We need more collections and a photograph.

Chroogomphus tomentosus © Michael Beug,     probable C. loculatus © Thom O'Dell

Chroogomphus pseudovinicolor ID - a reddish-orange to burgundy-orange very fat-stemmed species with a smooth, dry cap that is never umbonate. The confusing group of species below are not as stocky, often have a viscid cap and may be pointy. The only sequence we have is an unusually purple collection. I'd like sequences of more "normal" orange collections like the second photo below, or a type collection, to see if there's more than one species here. Parasitic on Suillus pseudobrevipes under pine.

Chroogomphus pseudovinicolor #1 (sequenced) © Andrew Parker,     C. cf pseudovinicolor #2 (unsequenced) © Danny Miller

Chroogomphus 'vinicolor PNW04' - may be viscid, but more pointy capped and darker red-brown than the following confusing species. So far the sequence we have from OR and the one from boreal BC do not match east coast type area sequences of C. vinicolor, nor do they match a CA sequence that might be subsp. californicus, so we may have our own variety in need of its own name. This theory is born out by ecology, as subsp. californicus is suspected to be parasitic on Suillus pungens, which is not proven north of CA, so ours is suspected to have a different host. We should get more collections to see if more varieties are present here as well.
Chroogomphus ochraceus PNW01/PNW02 OR - said to be viscid as well but less pointy and less dark than C. aff. vinicolor, but in practice very similar, except for microscopically having thinner walled cystidia, but even that may not be reliable. Two sister species are found in OR, one of them probably the real thing and one of them a lookalike sister species. We don't know how to tell them apart yet, nor even reliably from C. aff. vinicolor. PNW01 is found in OR and BC so far, PNW02 just in OR. We need more collections of all of them. Perhaps one of them may be parasitic on Suillus tomentosus under pine and perhaps there's a 3rd California species that may be parasitic on Suillus fuscotomentosus under pine.

Chroogomphus 'vinicolor PNW04',     C. 'ochraceus PNW01' and C. 'ochraceus PNW02' © NAMA and the Field Museum of Natural History

Chroogomphus 'ochraceus PNW03' - it may resemble C. ochraceus, but it sequences outside the group of the first two, closer to the secotioid C. albipes than it does C. vinicolor or C. ochraceus. The WA collection was bright orange and not at all umbonate. The CA collection was dark purple and not all umbonate. Being not at all umbonate may be how to recognize it.

Chroogomphus 'ochraceus PNW03' © Buck McAdoo and Michelle C. Torres-Grant (from CA)

Chroogomphus albipes group CA - even more secotioid than C. loculatus. we appear to have two genetic species here, not one, probably one of them the real thing and one of them in need of a new name. #1 is found in ID and OR. #2 is found in OR. No photos of sequenced collections yet.

possible Chroogomphus albipes group member © Ben Woo

Paxillus, Alpova and Melanogaster - click to expand

Paxillaceae - Large but thin-fleshed mushrooms with indented caps, a strongly inrolled margin, strongly decurrent gills that are often easily separable from the cap flesh and brown spores. The caps are large, yellow- to olive-brown discs and the mushrooms strongly stain brown.

Alpova and Melanogaster are trufflized mushrooms in the same family. Some ITS only trees show that Alpova is indeed a separate genus from Melanogaster, but it doesn't always show up that way. However, a 3-gene study was able to confirm with high confidence that Alpova is monophyletic and distinct.

Species mentioned: Paxillus involutus, cuprinus, ammoniavirescens, obscurisporus. Alpova diplophloeus, concolor, trappei. Melanogaster tuberiformis, macrocarpus, euryspermus, natsii, ambiguus, intermedius, broomianus, vittadinii.

While guidebooks have long said Paxillus involutus is the species here, under urban birch, it has recently thought that Paxillus cuprinus might be our species instead, but these DNA studies show that it is not an either/or, they are both here and so are two more. Telling them apart and figuring out which trees they each go with is the next step. Do not eat any of them, they contain a deadly toxin that can slowly kill you. The only bona fide report of a mycologist dying from mushroom poisoning was from this genus, before we realized the cumulative effects of the toxin.

Paxillus involutus EU - slender species said to be with urban birch, verified from Vancouver BC a number of times but trees not noted. Supposedly the DNA was found on a root tip of a Douglas fir.

Paxillus cuprinus EU -also slender, verified both with and without birch from BC, WA and OR. One collection was under native hazelnut, Corylus cornuta.

Paxillus obscurisporus EU - perhaps stockier and probably with hardwoods, found once in WA and once in boreal BC.

Paxillus 'ammoniavirescens IN01' - a similar stocky hardwood species with a more reddish-brown spore print (the others may be more yellow-olive-brown). NA collections sequence 3-8 bp different than EU type area sequences and may represent an undescribed species, but it may just be one species with variable ITS, as our sequences don't really stand out from EU sequences with strong support. Found in BC, WA and OR, trees not noted (possibly cottonwood).

Paxillus involutus © Hiba Mezerreg, P. cuprinus © Daniel Winkler, P. obscurisporus © Danny Miller, P. 'ammoniavirescens IN01' © Danny Miller

Alpova and Melanogaster - false truffles with a uniform dark, jelly-like oily marbled centre. Alpova are found with alder and sometimes not as pure black as Melanogaster.

Alpova

Alpova diplophloeus WA - under alder, fruity/garlicky odor, yellow-brown exterior bruising red, brown interior.

Alpova concolor OR - best differentiated microscopically.

Alpova concolor © Yi-Min Wang

Melanogaster

'Alpova' trappei OR - brighter yellow exterior when young, covered with some yellow rhizomorphs and not staining red. It belongs in Melanogaster with the darker species, which should have been predictable as it is with conifers not alder and ecology is always more important than colour for determining relationships. A southern species known only from OR and CA for now. It is not the same as Melanogaster luteus, which is a European false truffle with a very different sequence.

Alpova trappei © Matt Trappe

Melanogaster macrocarpus OR - a dark orange-brown false truffle perhaps with some dark rhizomorphs, with a black jelly marbled interior. Smells of onions and motor oil. It (and probably all local Melanogasters) have long incorrectly gone by the name Melanogaster tuberiformis EU, a closely related European false truffle not actually found here. M. macrocarpus is a >1% ITS variation species complex, but it's all the same species.

Melanogaster euryspermus OR - our second most common Melanogaster, with an odor of citrus and sewer gas. It is a 3% ITS variation complex (definitely on the higher end of ITS variation seen within one species), but all of them represent the same species.

Melanogaster natsii OR - we have the type sequence and one other, but it appears to be rare. I don't have a description yet.

Melanogaster PNW06 OR - unique DNA from any known species, supposedly found with Garry oak but the same DNA was supposedly also found on madrone and Doug fir roots. Found twice in southern OR and once near Eugene. It's possible this represents misidentified reports of one of the below species, but either way, it probably needs its own name.

Melanogaster ambiguus EU - we have EU DNA thanks to Alvarado 2021, and it has been reported recently from all over the PNW, but we don't have any local sequences to see if they really represent this species or not. M. euryspermus used to be considered a variety of this species, so it's possible reports of this actually represent that species. We need collections.

Melanogaster intermedius UK - we have likely UK DNA, and it has been reported from southern OR, CA and BC, but we don't have any local sequences to see if they really represent this species or not. This used to be considered another variety of M. ambiguus, so it's possible reports of this actually represent M. euryspermus, another former variety of M. ambiguus known to be common here. We need collections.

Melanogaster broomianus EU - we have EU DNA thanks to Alvarado 2021 to compare to, and it has been reported from OR almost a hundred years ago, but as it has not been found again in the extensive truffle research done by the Trappes, I highly doubt it's actually here. We could use some collections that key out to this to see what they actually are.

Melanogaster vittadinii EU - was reported once in OR, but nobody really knows what this species is supposed to be as it isn't a legally published name, so I highly doubt it was identified correctly. We do have one reported EU sequence to compare to, but that's probably not correctly identified either.

Tapinella - click to expand

Tapinellaceae - formerly these were all in Paxillus, because they too often have forked or interviened gills easily separable from the cap flesh.

Tapinella atrotomentosa EU - very large dark brown cap with strongly decurrent yellowish gills and a large, black-velvet eccentric stem on conifer stumps. Brown spores.

Tapinella panuoides EU - lacks a stem, on conifer stumps with brown spores. Yellowish brown cap and gills. The cap can be hairy when young. Hard to differentiate from Crepidotus except for the odd forked, crimped (wrinkled) or interveined gills near the point of attachment).

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