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Russula

Expert links: Compactae Fetid
Heterophyllidia Acrid tasting (emetica/rosacea, etc.) Shrimp
Greying Yellowing Mild, Cream to Yellow Spored

Russula is a very interesting genus of mushrooms, very different genetically from most other gilled mushrooms and in some sense not really a gilled mushroom at all. (Please read the introductory paragraphs of my Lactarius page for more background information). Russula is similar to Lactarius, but without milk. But unlike Lactarius, which can look quite different from each other, Russulas in the PNW look surprisingly similar. After browsing the illustrations on this page, you should at least be able to recognize a Russula when you see it, if not know which one you have.

You'll notice they all have a certain stature, and they mostly start out entirely white (although the stems can be flushed with pink, and the white can discolor, sometimes dramatically) with the possible exception of a cap cuticle that may be some bright colour. Also important is their brittle texture, like Lactarius, that allows the mushroom to break in any direction it is stressed, resulting in a Russula that is thrown against a tree disappearing into tiny bits instead of long stringy pieces like most mushrooms. This is more fun than it sounds.

Anybody who has worked with Russula will tell you that I am about to try to do the impossible here... tell you how to identify a Russula to species. One of my favourite quotes is from Anna Maria Hussey, from Illustrations of British Mycology in 1855: "If we know of any one, who in the pride of intellect spurned all mental tasks as mere play, we would tame him by insisting on his mastering, classifying and explaining the synonyms of the genus Russula." In other words, if you ever figure out how to identify all the Russulas, rocket science will be child's play. (Other difficult genera are Cortinarius, Inocybe, Psathyrella, Rhizophogon and the entire Entolomataceae family).

One of the main things that separates the Russulas is whether or not they taste mild or like a hot pepper (variously called peppery, acrid or hot, the same as for Lactarius). Chew a piece for 30 seconds to determine the taste, it may get hot slowly! The odor might also be sweet or flowery (like cherries or geraniums), fishy, or putrid like rotting food. Also, how much you can peel the coloured cuticle of cap skin may be important. Russulas are considered "white spored" mushrooms, but the truth is the spore print colour is usually some shade of yellow, from almost pure white to a deep orange-yellow. Unfortunately, the shade of yellow can range dramatically from individual to individual within a species, so I am going to try and avoid making you specify a shade of yellow, but just choose between spores that are white to almost white, or some shade of creamy yellow or darker. When Russulas get old, or scratched, the white flesh may turn yellow, brown, reddish-orange, or grey-black.  A few notable species have a pruinose cap, which is dry with a matte finish (not shiny with a glossy finish like most others) and slightly powdery in appearance. These are the important things to take note of. Most Russulas (and Lactarius) appear to be mycorrhizal, so you will usually find them on the ground under certain trees, often conifers (unless otherwise stated).

Russula spores (and thus mature gills) range in colour from white to cream to yellow (sometimes even orange). Make sure you check the oldest specimen you can find.

Unlike most gilled mushroom spores, Russula spores are rounder and are covered in warts that turn black in iodine.

You might have noticed that nowhere did I say the colour of the cap is important. It's not that I forgot, and it's not that I just assumed you knew that. Russula is also famous for having species with very variable cap colours. Sometimes it matters, but for some species it can literally be almost anything. The pigments are usually water soluble (and can fade to any shade) and the colour is probably also affected by moisture, pH, and who knows what else.

Most Russulas that taste mild are edible, but not incredible. There are exceptions, though. Russula subnigricans has killed people, but it has not yet been found in the PNW, although it has led to a recommendation not to eat its close relatives, the blackening Compactae. Some of the hot ones have upset some people's stomachs, although, as I explain with Lactarius, most seem to have been eaten successfully after careful preparation. Conversely, some people think that the better flavoured mild Russulas are some of the tastiest mushrooms around, because their brittle texture makes them crunchy instead of tough and chewy like most other mushrooms.

As usual, it is difficult to tell how big the mushroom is in real life from just a picture, so I have tried to indicate when a species is bigger or smaller than a "typical" Russula (5-10cm across). If yours is less than 5cm, consider the "small and fragile" species, and if it is larger than 10cm, consider one of the bigger ones.

Our largest (up to 20cm or more) common Russulas are the Compactae, the fetids, R. xerampelina grp, R. 'olivacea' and R. benwooii n.p. Occasionally members of the heterophyllidia can grow large.

Adnate to decurrent gills. They can be dry or viscid capped. Not hygrophanous. Never a partial veil. Found mostly on the ground.

This page is based on the collections of Ben Woo, a founding member and the first president of PSMS. He collected more than 1,000 Russulas across the PNW over a period of more than 30 years. Many thanks to Anna Bazzicalupo and her team for the critical study and sequencing of Ben's collection that made this page (and any true understanding our Russulas) possible. The species shown on this page are generally those for which we have actual evidence, but this page should not be considered complete. If half the Russulas found in this area can be identified using this page, it will have exceeded its goals. Most Russulas found on forays are never identified. Beware: you will have false positives (uncommon Russulas that look like something on this page, but aren't) as well as false negatives (sometimes the mushrooms described here will NOT have the characters I say they usually have).

 

Unfortunately, until my key is more complete, you will have to read through the following sections to determine which one most closely matches your specimen. Let's begin.

Compactae

There are thankfully a number of easy to recognize groups of Russulas, and one of them is the set of compact Russulas.

No, skip to the next group.

The compactae do not, in general, have proper names yet. These are for now just an attempt to group them, since the chemical that causes some of them to blacken seems to interfere with our ability to DNA sequence them. A new study will have to be done with fresh material.

R. 'brevipes' - a group of big short stemmed all white Russulas that barely push themselves out of the ground. They are edible.

R. cascadensis - usually smaller (<10cm), taste hot. Watch out for these.

Some large 'brevipes' have this strange little blue line under the gills, and are somewhat hot. We call them Russula brevipes var acrior or 'chloroides'.

These won't turn black, but they can sure turn brownish as they age! (Starting on the stem here).

Have you heard of the Lobster Mushroom? This is a mold, Hypomyces lactifluorum, that infects Russula brevipes. Unlike most molds, this one improves the texture and taste of the mushroom it is growing on.

Some Compactae turn blackish after a while. Often turning bright orange-red first. Most taste mild.

R. nigricans ('dissimulans') - with the widest spaced gills. Turns orange-red and then black when damaged or old. The cap is usually dry and not greasy or sticky. Can get large.

R. albonigra goes rapidly straight to black without reddening. It is also large. This and R. 'nigricans' may be found entirely pitch black (see photo on the right). May taste like menthol.

R. 'anthracina' - slowly greying. A drier capped R. adusta

R. 'adusta' - has a greasier, stickier cap. It may turn slightly red but slowly to grey, and is said to smell like wine barrels.

R. 'densifolia' sticky cap like R. adusta, with a more pronounced red phase. More likely to taste peppery than the others?

 

Fetid Russulas (Ingratula)

This group contains some Russulas with very interesting smells, but not all of them have a discernable odor. Most look similar.

No, skip to the next group.

R. cerolens ('sororia'/'pectinata') - tannish-brown, somewhat unpleasant odor? Usually with a dark stain in the centre of the cap. Creamy yellow spores. <8cm.

R. pectinatoides grp/granulata are occasionally found as well, usually without the dark stain and with red-brown granules on the cap, respectively, but they are all hard to tell apart.

R. laurocerasi grp ('fragrantissima') - May get large, brighter yellow-brown than R. cerolens, smells like maraschino cherries. Creamy spores as well. None of these taste any good.

R. foetens grp - Large, with nauseatingly sweet odor. <15cm.

R. pallescens ('farinipes') - in a second section, Ingratula II, with R. crassotunicata. Bright yellow-brown with a striate margin, but little odor, the smallest one with the whitest spores. The cap cuticle is harder to peel. Found with hardwoods. Tastes much more peppery than the others.

R. crassotunicata - also in Ingratula II. Entirely white to pale yellow. Browns quite a bit and most notably, the cap cuticle is a thick layer of gelatin that peels right off. Occasionally mild.

 

Heterophyllidia - mild, white to cream spored.

These are some of the most common Russulas in Europe and sometimes scorned even by Russula standards, but they are not so common over here. They are a distinctive, interesting group, yet it takes practice to recognize one.

I don't think so, skip to the next group.

R. brunneola - white spores, usually dark brown matte cap. Sometimes buttery gills.

R. smithii - described from the Olympics as green with a brown center and a pink flushed stem. White spores.

R. 'cyanoxantha' - white spores, large, matte cap mottled with purple, olive and other interesting colours. Flexible, buttery gills. Southern species. FeSO4 does not turn the cap flesh pinkish, unlike most other heterophyllidia.

R. 'aeruginea' - cream spores, greyish-green cap that is shinier than most other species.

Two other species have a matte cap. One has a cap cuticle that peels half way or more, and is not terribly unlike the east coast R. modesta.

R. mustelina - cream spores, pale young cap turning a matte dull brown without green but sometimes with pink or vinaceous tints. Sometimes found barely poking out of the ground.

R. 'grisea' - may also contain green, often with purple.

R. 'medullata' - cream spores, greyish-olive-brown matte cap, duller than other grey-green species, without purple.

At least 3 other greyish-brown matte to pruinose capped cream spored species are not well understood.

 

Emetica/Rosacea clade, etc. - hot tasting Russulas

This group, sometimes simply called the "Russula" subgenus, can be recognized by:

No, skip to the next group.

First, the most common white spored members:

R. emetica/montana (griseascens) - cap colours of poppy red, yellow, or both. 2/3 of 25 emetica specimens studied had red colours. Only 1/3 of 25 griseascens specimens did. Consistently acrid.

Traditionally named for if the caps had red or were pure yellow: emetica, bicolor or silvicola for red; crenulata*, cremoricolor*, raoultii or ochroleuca for yellow. The red fades, so is not a good indicator.

(*described from the west coast and may one day be matched to this species group).

R. parapallens n.p. - pink or yellow or both, but not as bright as the R. emetica grp, sometimes with splotches of purple brown. It is also just as likely as not to be mild, or have a pink flushed stem like R. rosacea. (Spores may be white or yellow).

R. stuntzii - whitish with tinges of grey. Lavender colours may be present, but usually with grey (unlike 'fragilis'). Occasionally mild. Slight buff tinge to the spores.

R. hypofragilis n.p. ('fragilis') - dark purple, purple-red or purple-brown, but may fade around the edges to white, with the centre usually still coloured. Not as fragile as the true R. fragilis.

R. phoenicia n.p. ('fragilis') - very similar, but perhaps more likely to have olive colours mixed in. May taste mild.

Next, the most common related cream to yellow-spored species:

R. rosacea var. macropseudocystidiata ('sanguinaria'/americana?) - poppy red like R. emetica, with a red flushed stem. May smell like geraniums. Cream spores. May be mild.

R. rhodocephala n.p. - very similar, perhaps a bit duller red or a bit less of a stem flush. Unlike the above, usually only under pine. Usually hot.

R. salishensis n.p. ('pelargonia') - reddish-purple cap often with purple centre and a slightly flushed stem. Cream spores. Strong geranium odor. Also occasionally mild. With douglas fir and hemlock.

R. pseudopelargonia n.p. - very similar, perhaps more fruity than flowery. Found as above or under true fir. Usually hot.

R. queletii ('sardonia'/'torulosa') - very purple with a purple flushed stem. Cream spores. Fruity or geranium odor. Frequently reported as mild. Found with spruce and pine.

R. parapallens n.p. - pink or yellow or both, but not as bright as R. rosacea, sometimes with splotches of purple brown. It is also just as likely as not to be mild, or have a pink flushed stem like R. rosacea. (Spores may be white or yellow).

Finally, the cream to yellow spored species not related to this group, but easily confused with it.

R. mordax ('veternosa') - usually pinkish-orange, often with yellow areas. Maybe a slight flush on the stem, but little browning, with somewhat dark yellow spores. Oddly, perhaps related to the mild R. vinosa and R. sierrensis. May be mild tasting or with a pleasant sweet or floral odor.

R. firmula - with only an occasional bit of stem flushing at the base and an occasional fruity or floral odor (and occasionally mild?), it is usually more dark purple with less red than most others in this section, and has fairly dark yellow spores.

R. versicolor - small, under birch; often purple but also shades of red, yellow or green. Turns yellow, but maybe only a little near the bottom of the stem. Mild flesh but slightly acrid gills, and dark yellow spores. Best recognized by the birch trees and eventual yellow stains. Related to the also yellowing R. nauseosa.

 

The rest of the Russulas are in a subgenus sometimes called the "crown" or affectionately, the "garbage" clade. Let's go through them.

Shrimp Russulas

The Russula xerampelina group deserves its own category. They are probably the most common Russulas around and said to be the best tasting (for a Russula, which might not be saying much), but unfortunately they can come in almost any colour. In the space of a single hour, I once saw yellow, orange, brown, green, red and purple ones, although they are "usually" dark purple. So forget trying to ID them by cap colour, you are looking for the following combination of characters:

Actually, if you have a good nose, the shrimp odor is all you need to know. Just give it a sniff where the gills meet the stem, especially a few minutes after scratching them. But for young specimens, or those like me who can't always detect the shrimp odor, you'll need to know the other characters. A drop of FeSO4, if you are chemically inclined, on the cap and stem flesh will turn greenish, which is not a common reaction for Russula. (FeSO4 is sold in garden stores as iron sulphate).

Compare them with R. 'olivacea', a fairly close relative, which is similarly large but has a dryer cap sometimes like kid leather, denser flesh, stains less brown and does not have an odor. It does not turn green in FeSO4.

 

 

 

The green with dark brown centred form is often a separate species called R. 'elaeodes'.

The pale pink- or yellow-brown version with little stem flushing is a separate species called R. isabelliniceps or viridofusca.

 

Before continuing, consider R. 'olivacea'.

R. 'olivacea' - large, dry, purple-green, velvety cap that doesn't peel much, stem flushed pink. Almost like R. xerampelina (and closely related to it), but with darker spores, more dense flesh, little brown staining and no odor. FeSO4 not green.

 

Greying Russulas - mild, cream spores

While in many Russulas the flesh, stem and gills will turn from white to brownish as they age, the following two species (not especially related to each other) turn grey. This can be hard to detect, as the reaction may take hours after it has been handled! Many other Russulas will get small grey spots, but these will often (hopefully) eventually turn more grey than most. They may even turn a little red first, but they differ from the blackening Russulas by not blackening (just greying), and by having some kind of colourful cap. They are mostly mild tasting with cream spores (and mature gills).

No, skip to the next group.

R. vinosa ('occidentalis') - usually olive-brown perhaps with red or purple tinges on the edge. Usually Mild. May turn reddish and then grey where handled or injured. The larger (more often >10cm) R. benwooii n.p. may have a constant lilac-grey tint to the stem. R. mordax and R. sierrensis may be related, but do not grey, and so are described in other sections.

R. vinososordida ('decolorans') - usually orangish, but often with reddish brown or wine colours. The greying may be slow and subtle. Usually mild, but may be slightly acrid.

 

Yellowing Russulas - mild to somewhat acrid, yellow spores

A few related Russulas turn yellow as they age instead of brown, one of them quite dramatically. They both have a striate, somewhat viscid cap.

No, skip to the next group.

R. nauseosa ('puellaris') grp - Usually purple but like so many others can fade dramatically. Cream to yellow spores, small and fragile, mild, and eventually starts turning yellow almost everywhere. At least two cryptic species.

R. versicolor - small, under birch; often purple but also shades of red, yellow or green. May only turn yellow a little near the bottom of the stem. Mild flesh but slightly acrid gills, and dark yellow spores. Best recognized by noting the birch trees and scratching it to see if it eventually turns yellow.

 

Mild, creamy yellow to dark spored Russulas

Most mild creamy yellow spored Russulas will not be Heterophyllidia. There are also mild, dark yellow spored species. (If you find a young one before the spores have matured, remember that the gills will still be white). And as noted above, some acrid species are sometimes reported as mild, so you may have to check there too. The stems do not usually have a pink flush nor do they brown much in age. (Also check R. xerampelina and R. 'olivacea').

R. 'turci' grp ('murrillii'/'amethystina') - one is quite common, with a second not uncommonly found (and rarely a third). Matte cap that is often pruinose, usually purple, although it might be almost anything. Cream spores. Some specimens smell like iodine in the base.

R. lutea (postiana/chamaeleontina) - a related yellow, shinier capped mushroom with very dark yellow spores. Found mostly with hardwood.

R. olivina - similar, yellow cap may be mixed with tan or orange tones. Not related but hard to tell apart from R. lutea.

R. zelleri ('cessans') - usually shiny, purple to purple-brown caps (compare to R. turci). Found with spruce and pine. Yellow spores.

R. pseudotsugarum n.p. - zelleri grp member that may also be found with douglas fir and hemlock.

R. rhodozelleri n.p. - also with any of those tree hosts, this member tends to have more red tones than the others, similar to R. sierrensis. Cream to yellow spores.

R. graminea - green to olive-yellow capped member of the zelleri grp.

R. sierrensis - reddish purple caps with yellow brown splotches, but quite variable and not well understood yet. Very similar to the R. zelleri grp. Perhaps related to R. vinosa and R. mordax. Yellow spores.

R. benwooii n.p. - One of our largest and most common Russulas. Often less colourful than the others, greyish-brown, but it is quite variable and might look just like zelleri, graminea or sierrensis. Often reported with a vinaceous-grey tint to the stem, unlike the others, but not quite like the greying group which discolours more over time.

It is likely that large specimens have been mistaken for R. xerampelina and vinaceous and olive versions were being called R. 'occidentalis'. If your specimen is reliably <10cm and truly greys, you may have the actual R. vinosa. Cream spores.

 

Congratulations! You now know more about PNW Russula than most people. Russulas can be an intimidating group to study, so most people do not bother to try and learn more than a few distinctive species, but if you work at it a little bit, you'll soon be able to impress your friends. But don't get frustrated when even with this page, you may still find as many Russulas you can't identify as those that you can. You're in good company. A quick look through GenBank shows that most of the Russulas that are in fact the same species have many different names, and looking at Russulas with the same name shows that many are completely unrelated to each other. For specialized literature for those of you who want to learn more, you will need to learn Italian or French, as there are no comprehensive illustrated English language books about Russula besides Fungi of Switzerland Vol. 6.

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