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Danny’s DNA Discoveries – Russula
by Danny Miller
Introduction - read this for a background on Russula
R. nigricans © Ben Woo and Danny Miller
These two clades of Russulas are easy to recognize, and used to be thought of as one group, but they form two separate genetic clades.
completely white when young (other Russulas have a coloured cap cuticle and may be whitish, but not usually this white)
stain brown in age, sometimes a lot
quite dense (thus the term "compact") and heavy
have subgills (shorter gills that don't go all the way from stem to cap, most other Russulas don't)
there is no top cap layer to peel off easily (there is a coloured cuticle on most other Russulas that peels, at least somewhat)
Compactae: these turn black in age (first photo), sometimes with an intermediate red phase (second photo). It can be quite striking!
Brevipes: do not.
R. cascadensis - small (<9cm), hot tasting with a creamy yellow spore print.
R. brevipes group - will grow larger than 10cm, mild or hot tasting, almost white spore print. We have about 6 species in this group, none with a name, and none are actually R. brevipes itself.
R. nigricans and R. albonigra - do occur here as thought
R. adusta group - we have 3 species in this group, perhaps including the real R. adusta
R. acrifolia - what we have been calling R. densifolia is actually closer to R. acrifolia, if not the same thing, so use that name for now instead.
R. laurocerasi group member © Joy Spurr, R. cerolens © Ben Woo and R. crassotunicata © Kit Scates Barnhart
These similar mushrooms used to be grouped together in one clade, Ingratula, until it was discovered that the similar R. pallescens belonged in a separate clade with the unique R. crassotunicata. They taste somewhat peppery, which is bad enough, but even worse than that, they often have this putrid, nauseating odor and flavour that kind of makes you want to throw up. So, they win the worst tasting Russulas award. Although, I once had a professional chef prepare one of these (sp. Woo 3) to see if it could be made palatable, and a few of us ate some, and it didn’t suck. But definitely not recommended.
most of them have a yellow-brown to brown cap cuticle with a strongly striate margin
often taste somewhat peppery. Ingratula have a putrid, nauseating odor and flavour
some brighter yellow-brown ones (first photo) smell nauseatingly sweet like marashino cherries, the plain brown ones (second photo) do not.
if you cut a fresh Ingratula stem lengthwise, you may find hollow diamond shaped chambers.
the odd one out (third photo) is white (but browns considerably) with a very thick, peelable gelatinous cap cuticle.
R. cerolens - very common, mistakenly called R. sororia, R. pectinata or R. pectinatoides.
R. recondita group - 3 rare, closely related species best differentiated from R. cerolens microscopically
R. 'foetens' - unnamed species often reported as unpleasantly nauseatingly sweet like vomit
R. 'laurocerasi'/'fragrantissima' group - 2 unnamed species often reported as pleasantly sweet like almond or maraschino cherries
R. pallescens - rare, almost yellow, small, slender species with white spores (the others have cream spores), no odor. Mistakenly called R. farinipes
R. crassotunicata - common, all white, browns significantly, cap cuticle is a thick, gelatinous, peelable layer.
R. sp. Woo 13, R. 'aeruginea', R. 'brunneola' © Ben Woo
This group needs the most study. They are difficult to identify and not much is known about them. They just aren’t found often enough to study and most of the time when one is found, it isn’t recognized. That’s unfortunate, because most if not all of the group members are mild tasting and especially dense and crunchy textured making this group potentially among the better tasting Russulas (although none have been tested enough to be sure of their edibility). There at least a dozen species, and few of them have been named yet or even have a good description. Here is a not-at-all foolproof way of trying to identify this section:
spores white to cream (not usually that dark of a yellow)
mild tasting and often dense
sometimes the caps are matte or even pruinose (but not always) instead of shiny and sticky, which is quite beautiful.
gills might be flexible and buttery instead of brittle.
more often in brown, green and grey colours, only rarely the red wine colours you see in other Russulas
the flesh may or may not brown in age and usually there is no coloured stem flush, but that’s not always the case.
the microscopic spot where the spore attaches to the basidium is small and doesn’t darken in iodine as much as it does for other Russulas
So... a Russula with a matte, pruinose or powdery cap (left photo) might be one of these (except the very common purple capped Russulas in the R. murrillii group). Any green Russula, even with a shiny cap (middle photo), might be one of these. That can be really subtle, a wet cap can hide the matte-ness and any dry cap might start to look matte. Brown, pruinose caps are common in this group (right photo).
R. 'aeruginea' - our least uncommon member, a shiny green capped species. Other Russulas are very similar, like R. graminea.
R. sp. Woo 13 - a beautiful matte, green capped species, other species are not entirely green but with a lot of brown.
R. 'brunneola' - a matte, brown capped species with white spores (almost all others have cream coloured spores).
R. 'mustelina' and 'medullata' - two matte, brown (maybe mixed with other colours), cream spored European species, but a half dozen undescribed species are similar.
R. sp. Woo 16 - a beautiful purple, matte capped Russula, but with a purple flushed stem (unlike the much more common R. murrillii group).
R. malva np - mistakenly called R. cyanoxantha, this large, matte capped southern Russula has mottled purple colours (mostly found in California) has a provisional name. Some analyses show it in a separate clade, which I call Heterophyllidia II. FeSO4 does not turn the flesh of this species pink, unlike the other Heterophyllidia.
Amoenula, Archaeae, Malodora and Glutinosae Clades
We do not appear to have any Russulas from these sections in the PNW, so we’re not going to learn anything about them today. If you can find one, you’ll be famous. Russula mariae from the east coast is in clade Amoenula, but reports of that species in the west have not been proven yet.
R. emetica, R. phoenicea, R. americana © Ben Woo
The “core” species (most closely related to the official first Russula, Russula emetica), are not recognized so much by how they look, but by the fact that they are often hot tasting and don't belong to one of the previous groups. A surprising number of species come in either poppy red or yellow (or a mixture, left photo). Some species have a lot of stem flushing (right photo). Unfortunately, the chemical that makes them taste hot can go away or wash out, so sometimes they taste mild. A drop of sulfo vanillin will usually turn the flesh of a “hot” species purple (in this clade or elsewhere), even if a certain specimen tastes mild. This was one of the most interesting results of Anna’s study of Ben’s chemical tests on his Russula collection.
any white spored Russula not found in previous sections is probably in this section, whether or not you can detect the hot taste.
hot Russulas with cream spores are usually found here. Make sure to rule out the very common, darker yellow spored R. mordax (and the rarer purple, spruce Russulas R. firmula and R. ‘punicea’, and R. versicolor), found in the Crown clades below
a core clade cream spored Russula that doesn't taste hot is going to be difficult to identify; you'll have to learn their individual characters
Most species are together in one clade, but a few white spored species live in the cream spored clade (R. stuntzi, R. parapallens, R. aff. viscida). These three won't necessarily have pure white spores, but could have a little tint to them.
R. emetica/montana - two very common similar mushrooms that can be poppy red, yellow, or both. R. montana's stem may grey in age, but best distinguished microscopically. At least two other rare species are almost identical. The local R. crenulata exists but not much is known about what it really is. These have been mistakenly called R. bicolor or R. silvicola in the past.
R. parapallens - also common and bright red and/or yellow but usually with a dark splotch of colour on the disc. Two rare species (R. laccata and R. 'viscida') are similar but perhaps closer to wine-red, with the stem of R. 'viscida' browning considerably in age.
R. phoenicea/hypofragilis - have purple tones. R. phoenicea also has green/olive tones. These have mistakenly been called R. fragilis in the past.
R. stuntzii - grey cap that may have purple tones.
R. americana/rhodocephala - poppy red caps with poppy red flushed stems, differentiated by their tree associates. Mistakenly called R. rosacea or R. sanguinea in the past.
R. queletii - purple caps with purple flushed stems. Mistakenly called R. sardonia or R. torulosa in the past.
R. pseudopelargonia/salishensis - reddish-purple caps with a bit of stem flushing, difficult to differentiate from each other. Mistakenly called R. pelargonia before.
A handful of rare species have red, yellow or white caps. They are unnamed, poorly understood, or both, and resemble and/or are close relatives of R. alcalinicola, R. albidula/persicina and R. renidens.
The remaining Russulas have not been definitively separated out into smaller groups yet, unfortunately, and there are a lot of them. Around half of the Russulas fall into this large clade. There have been many smaller groupings made over the years, but they have not proven to be genetically valid groupings, so I’m going to treat them all as one large group. It gets its name from the fact that they may represent the newest branches, at the “crown” of the genetic tree. I also call them the “garbage” clade, since you can think of these as species that did not end up fitting into any smaller, well defined group, but instead got thrown in to the large garbage bin of clades. They tend to have relatively dark, yellow spores (usually darker than the hot “core” clade Russulas) and are mostly mild, with a few notable exceptions. The many mild species vary a lot in their density, texture and flavour, so some make better edibles than others. Many people indiscriminatly eat all mild Russulas with relatively few reported poisonings, but most cannot be identified reliably so the edibility of most species is still officially unknown. A few species, like the shrimp Russula aff xerampelina are popular edibles. Let's break them down into sub-clades:
R. mordax © Ben Woo
Although most of these species are mild, unfortunately a few of them are hot, making them easily confused with the “core” clade.
R. mordax - perhaps our most common Russula, often reddish with a paler disc (see photo). Mistakenly called R. veternosa.
R. firmula/'punicea' - two rare hot, purple, coastal spruce Russulas
Russula versicolor - found under birch, may be hot tasting in the gills and is described below under the yellowing Russulas.
R. sp. Woo 61 (aff xerampelina, R. viridofusca, R. favrei © Ben Woo
These are some of the most popular edibles in Russula, probably because they are easier to identify than most, not because they are the best tasting. They are not as dense and well-textured as some other species, but the shrimpy-ness disappears in cooking. The cap can be many different colours, but the following combination of characters identifies them:
they smell like shrimp, at least in age
a drop of FeSO4 turns them green, which doesn’t usually happen in any other group.
the flesh is especially susceptible to browning
the stems are sometimes flushed pink
the spores are rather yellow so the gills are quite yellow in age
Also in this section I discuss our local species that resembles R. olivacea, which differs in significant ways.
does not smell like shrimp, does not turn green in FeSO4, does not brown much, and is much denser. It's cap is usually purple and/or green. It is also large with significant stem flushing.
R. sp. Woo 61 (aff xerampelina) - usually a wine-red cap (left photo) with significant stem flushing
R. viridofusca - usually a yellow-brown cap (centre photo) without much stem flushing. Sometimes referred to as R. isabelliniceps np
R. favrei - usually a brown cap with a dark brown disc (right photo), also without much stem flushing. Mistakenly referred to as R. elaeodes
R. sp. Woo 58 (cf olivacea) - described above. We do not actually have the real R. olivacea.
R. vinosa, R. 'vinososordida' © Ben Woo
Some Russulas with brightly coloured caps will turn grey after you scratch the stem (as the white Compactae group can). They might also turn reddish before turning grey. Two separate sub-clades have species that behave this way (although not every species in the clades exhibit this feature). The two most common species are not that closely related (one is in each sub-clade).
R. vinosa (occidentalis) - purple/green cap (left photo)
R. 'vinososordida' - orange cap (right photo)
R. 'californiensis' or something close, which may occur this far north (rosy-red cap) as well as a rare species with a dirty yellow-brown cap are to be looked for.
R. sp. Woo 45 (cf abietina) © Ben Woo
Some Russula stems and other fleshy parts will turn a fairly bright yellow in age. They seem to make up a good sub-clade of related species, although not every species in the clade may exhibit the yellowing staining very easily.
R. puellaris group - we have been incorrectly calling these R. puellaris. We have two common conifer species, R. sapinea and something we are calling R. 'abietina' but may or may not be that, and a third rare unnamed species.
R. versicolor - with birch, the only reported acrid tasting species. The colours are, as the name implies, variable and the yellowing on the stem is subtle.
R. murrillii group member, encrusted primordial hyphae © Danny Miller, R. 'turci' and R. postiana © Ben Woo
These purple (or reddish-purple) members have pruinose or matte purple caps, the texture you often see in the Heterophyllidia clade, but they are more fragile and less dense, with darker yellow spores. Microscopically, you can identify the reason for the pruinose cap by finding “encrusted pileal primordial hyphae”. Pileal means in the pileus cuticle, the top layer of the cap. They are crusty bumps on the walls of otherwise cylindrical cells, a few of which are pointed out in this micro photo:
In this section I also cover yellow Russulas that may or may not have the encrusted cap hyphae - but even if they do, they do not demonstrate it with a matte/pruinose cap texture; they usually have regular, somewhat shiny caps.
R. murrillii group - we have the local R. murrillii, the European R. 'turci' and a rarer unnamed third species, with purple to reddish-purple matte/pruinose caps. They somewhat resemble the rare, unrelated R. sp. Woo 16, but that has a purple flushed stem.
R. postiana - rare, shiny yellow capped species with the encrusted cap hyphae, but not enough to make the cap matte. The spores are especially dark yellow. Mistaken for R. lutea.
R. olivina - rare, shiny yellow capped species without the encrusted cap hyphae.
R. pseudotsugarum © Ben Woo
This is a group of at least 5 related species, very hard to tell apart. For the most part, they are somewhat fragile, mild tasting, purple (sometimes with red), yellow spored Russulas with normal shiny caps. Five of them definitely match that description; two other mystery Russulas are somewhat related but look different. They are much like the R. turci group except they don’t have the encrusted pileal primordial cystidia, so they do not have a matte or pruinose textured cap.
R. zelleri group - mistaken for R. cessans, this group of purple to reddish-purple smooth/shiny capped species (in contrast to the matte/pruinose caps of the R. murrillii group) includes the common R. zelleri, R. obscurozelleri and R. pseudotsugarum. Two rarer species do not yet have names nor descriptions.
© Ben Woo - R. graminea, R. sierrensis, R. benwooii, R. benwooii
R. graminea - (first photo) a not uncommon smooth, green capped Russula easily mistaken for the Heterophyllidia R. aeruginea.
Two rare species, sp. Woo 48 and sp. Woo 49, of which little is known.
R. sierrensis - (second photo) a not uncommon highly variable mushroom with a red, purple, brown (or all of the above) cap, easily mistaken for the R. zelleri group and others.
R. benwooii - (last two photos) a very common large Russula mistaken for R. 'xerampelina' shrimp Russulas or R. vinosa. It is often (but not always) brownish tan, perhaps with areas of olive, and a stem that may be slightly flushed grey or vinaceous.
Once, under introduced birch in Seattle, something close to R. velenovskyi was found.
Summary of Future Studies Needed
Brevipes and Compactae
Figure out how to distinguish the half dozen or so members of the Russula brevipes group and name those that are distinct species.
Determine if R. atrata is distinct from R. albonigra.
Determine how to distinguish the three members of the R. adusta group and which constitute new species.
Determine if hot taste reliably separates R. aff acrifolia and if it is a unique species needing a new name.
Ingratula and Crassotunicata
Investigate reports of R. granulata
Determine how to differentiate the three R. recondita group species and put names on them.
Determine how to better separate sweet smelling species 3, and 4 (and if 4a is a unique species or not), and put names on those and sp. 5.
Study the entire Heterophyllidia group, there’s not much that
doesn’t need study here.
Determine what R. crenulata is and if it’s sp. 24 or 24a.
Figure out if our species is the real R. laccata
Figure out if R. sp. 29 is R. viscida or not
Better ways to distinguish R. salishensis and R. pseudopelargonia, including how to recognize sp. 38.
A better understanding of sp. 31, sp. 33 and R. alcalinicola.
Figure out what R. flava var pacifica is
Distinguishing R. firmula and R. ‘punicea’ including getting a proper name for R. ‘punicea’.
Give a new name to our R. ‘olivacea’
Investigate how to recognize greying species 56 and 65 and give them names
Sort out the yellowing group – Name #42. Figure out if we really have R. sapinea. Figure out what R. abietina really is and is it #45 or does that need a name?
Why are R. murrillii and R. turci sometimes described backwards from each other? How to tell sp. 71 apart from those two.
Sort out how to recoginze the various members of the R. zelleri group, especially how to recoginze sp. 51 and sp. 51a.
Learn something more about sp. 48 and sp. 49, of which really nothing is known yet.
Get a good description of the many faces of R. sierrensis and how to recognize it.
Figure out if we have R. velenovskyi or if ours needs a new name, and how to recognize it better.
Solve the mysteries of what are R. placita, R. marina, R. inconstans and R. maxima
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