Danny’s DNA Discoveries – Russula
by Danny Miller
Clade Russula “crown” - Hot Species
Although most of these species are mild, unfortunately a few of them are hot, making them easily confused with the “core” clade. Russula versicolor, found under birch, may be hot tasting in the gills and is described below under the yellowing Russulas.
Russula mordax
Arguably our most common Russula, found with doug fir and hemlock, our most common trees. It is usually very acrid. The cap is reddish, sometimes pinkish to orange, and there is usually a paler splotch of yellow-orange in the center, unlike other species that have a darker center. It may have a slight stem flush but doesn’t brown very much. The odor is often floral, also causing confusion with the “core” clade. As you can see from the second photo, it is of course susceptible to colour variations and unfortunately won't always have its typical colouration. We have been calling this R. veternosa for years, a similar only somewhat related European species. In 1936, Burlingham found and described this species from Seattle, but it appears that nobody noticed until the study of Ben’s Russulas revealed that more local Russulas matched this species than any other single species, and they were all a match to the type of R. mordax, often an exact DNA match. We wouldn’t have needed DNA studies to figure this out if we had paid closer attention to her publications. Russula tenuiceps, an east coast oak species, is said to be very similar (and if the same, that older name would take precedence), but although Russula mordax has been found under oak here, others think the species do show enough differences that they are not likely the same. Somebody please study east coast oak specimens so we can find out for sure. This mushroom is in the same general clade as the red-grey staining Russula vinosa, along with a few others, but it does not demonstrate that property, nor is it mild like the rest of them.
R. mordax © Ben Woo and Steve Trudell
Russula ‘firmula’
This uncommon hot purple Russula is found with coastal spruce, so it very much resembles R. queletii but usually without the prominent stem flushing. It has much darker yellow spores. Our local species is about 2% different in DNA than the European R. firmula, about twice as many differences as I’d like to see, but those differences are often in long strings of the same letter where it can be hard to get an accurate read, so the jury is still out if this a different species. The differences are consistent across the ocean, though.
R. ‘firmula’ © Ben Woo
Russula ‘punicea’
This fairly rare (up north in the PNW) closely related wine coloured Russula is also found with spruce on the coast and also may have a stem flush like R. queletii, but it usually is redder than the other two (again, with darker spores than R. queletii). It was described from California in 1997, but unfortunately the name R. punicea was already taken back in 1945, so it needs a new name. We don’t have a type sequence to prove this species is R. punicea, but these collections are from the same area and the descriptions match very well.
R. ‘punicea’ © Ben Woo