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Danny’s DNA Discoveries – Russula

by Danny Miller

 

Clade Russula “core” - Cream Spored Members

The gills of older specimens of these species will not stay pure white like they do for the previous species, but turn yellowish-cream (but not usually a dark yellow). Remember, young specimes will have white gills before the spores mature.

 

Russula americana

This species not only has a poppy red cap (like Russula emetica can have) but a poppy red stem flush as well. Thankfully, it does not fade to yellow and is pretty consistently red. As is often the case, this species may occasionally taste mild. It is found with fir and hemlock. Sometimes it will have a floral aroma, like geraniums, which is also common in other members below. The mouthful of a species name Russula rosacea var macropsuedocystidiata is the same thing, just a newer name from Washington in 1979 (described by Darryl Grund) whose type may or may not have a single ITS1 difference from most other collections that have subsequently been found. I do not have a type sequence of R. americana to prove it, but all evidence points to the fact that this common species is what was described in 1940 as R. americana.

R. americana © Ben Woo

 

Russula rhodocephala

This species is very similar, perhaps a little more robust, perhaps with the stem not quite as flushed, but found with pine. It is pretty consistently hot tasting. It has long been assumed that our pine species was the same as the European R. sanguinea, R. rosacea or R. sanguinaria, but that is not the case (those species do not occur here), so this red Russula was described out of Ben’s studies. When the stem is not very flushed, it could be mistaken for some of the rarer species shown later in this section.

R. rhodocephala © Ben Woo

 

Russula ‘queletii’

Purple capped with a purple flushed stem, also found with pine, also may have a geranium odor, sometimes reported as mild tasting. The cap may fade to expose yellow and olive tones. The similar R. sardonia and R. torulosa that have been reported from here do not actually seem to be here, only R. queletii. There are two possibilities for what constitutes an official R. queletii sequence. Ours matches (within 3 total ITS nucleotides) some experts’ opinions of which is the real one, but not everybody’s. If the real one is the other one, this may need a new name.

R. ‘queletii’ © Ben Woo

 

Russula salishensis

This new species name comes from the fact that its range is approximately that of the salish tribes, both west and east of the mountains. This is one of two somewhat intermediate species between R. queletii and R. americana/rhodocephala. Russula salishensis occurs with douglas fir and hemlock, has a reddish-purple cap, only a bit of a stem flush and its cap also may fade to expose olive or yellow tones. It too may smell of geraniums and may be mild. Until Ben’s study, this new Russula had always been mistaken for R. queletii or R. pelargonia (discussed next). The more purple specimens with a stem flush look like R. queletii. The more reddish specimens look like R. pseudopelargonia. This species is only two nucleotides different in its ITS2 region from R. queletii and can be hard to distinguish from it without a microscope. On average, you might see at least 4 differences between species. Because 1 to 2 nucleotides is not very much, you can’t really distinguish this species with a simple DNA comparison without looking at the individual nucleotides carefully and the ecology.

      

R. salishensis © Ben Woo

 

Russula sp. Woo 38

One specimen of a closely related, possibly new species #38 was found in NE Oregon with a creamy white cap, almost devoid of colour. It tasted mild. I do not know how we will be able to recognize it again; more sampling will have to be done.

 

Russula pseudopelargonia

This species was so named because it was mistaken for the Eurpean R. pelargonia but it is a new local species. It is very much like R. salishensis (and grows with the same doug fir and hemlock trees) and might best be distinguished microscopically. Only found west of the cascades so far, and pretty consistently hot. It does not seem to fade to olive and yellow tones easily like the other two. New PNW species that have been mistaken for a similar European species are, not surprisingly, usually closely related to that similar European species. But in this case, the real Russula pelargonia may not be closely related at all. It just looks a whole lot like it.

R. pseudopelargonia © Ben Woo

 

Russula sp. Woo 31 (aff renidens)

Now for some rare, poorly understood, hot Russulas with cream spores. Russula renidens is a European species found with willow with a pinkish red cap that may fade to expose creamy yellow tones, and with only a slight stem flush. It is very similar looking to another European species, R. persicina. Our sister species (about 5 bp and 2 indels different in ITS1 and 6 bp in ITS2, probably enough to justify a new species) was found once in Idaho with larch, pine and aspen, and once in Alaska with spruce, aspen and birch, so it’s unclear if it’s also a hardwood species. It will likely need a new name. When completely pinkish it could be mistaken for specimens of Russula rhodocephala that don’t show much stem flushing, but that is definitely a conifer species. It may have a sweet odor. The Alaska collection had flesh that greyed when cut. Both collections had many irregular splotches of faded pink/red where it was quite pale underneath, so that seems to be a good character.

R. aff renidens © Ben Woo

 

Russula sp. Woo 33 (cf albidula/aff persicina)

This hardwood associated pinkish red species can also be entirely cream or yellow capped. It may or may not be hot tasting and have a pleasant odor. It not only resembles Russula persicina when red, but is closely related to it (although R. persicina does not appear to complety lose its red tones). In California under oak, a genetically similar species (2-4 ITS2 differences) is so far always white-yellow , where it has been called Russula albidula, but that is an Alabama pine species so it may not a correct name (wrong climate, completely different kind of tree). Since it looks like R. albidula (in its white to yellow form) I am calling it “cf albidula”. I also call it “aff persicina” because it is actually closely related to that species (although it is distinct, at 3.5% different in ITS2). Our local PNW species is at least 1% different than the California oak specimens, so it may or may not be the same (especially if it’s true that it is only yellow when found in California with oak). Here in the PNW, it was found in two places, in both colour forms with cottonwood near the Columbia River next to Mt. Hood and with a yellow cap with birch in a Seattle parking strip. When pinkish-red, it could be confused with Russula aff renidens or specimens of Russula rhodocephala without the stem flushing, but again, that is a conifer species.

R. cf albidula/aff persicina © Ben Woo

 

Russula alcalinicola (exalbicans?)

Russula alcalinicola is a Wyoming species found under greasewood (so probably a hardwood species) with a creamy white cap. It’s apparently often hot and has a fruity odor. It was found once at Mt. Hood, but unfortunately the nearby trees were not noted. It likely has almost identical DNA (~1 ITS1 difference) as the older, European species R. exalbicans (but not necessarily, as there is some disagreement as to what the true R. exalbicans is). That species is found only with birch and starts out red and fades to paler colours, whereas R. alcalinicola has only been found (so far) already completely pale and not with birch. Perhaps they are different, so we’ll refer to our species as R. alcalinicola. Although it is rare, Ben did correctly identify this Russula, so it does seem to have distinctive qualities. It could be mistaken for Russula cf albidula in its pale form.

R. alcalinicola © Ben Woo

 

Russula gracillima

The European species R. gracillima, which may or may not be the same as the Vermont species R. gracilis, was found in Northern BC in Hazleton, not quite the PNW, but if reports from California of R. gracilis are correct, and the same species, it is to be looked for here.

 

Russula flava var pacifica

This yellow capped variety was described from Oregon in 1930 under conifers, but it is not at all related to the “crown clade” species R. flava (see those pages) but instead belongs in this “core clade” of creamy yellow spored species. It did not turn red nor grey like R. flava does and does not match it at all microscopically, so it should never have been placed near R. flava. However, absent a sequence of the type, we don’t know what it is. I can’t see a good match to the above species, as most of the species that can have a yellow cap are likely hardwood species. It will definitely need a new name, if it isn’t a duplicate of an existing species.

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