Details about map content are available here Click on the map dots to view record details.
Species Information
Summary: Clade Russula crown. Features include 1) a cap that is greenish, pinkish, dark red, vinaceous, purple, or brown, or combinations of these, 2) gills that become yellowish, 3) a white stem that varies in length and often widens downward, 4) a mild odor and taste, 5) a cream to yellow spore deposit, and 6) growth under Douglas-fir. |It is a member of the Russula zelleri group along with Russula obscurozelleri. The members of the Russula zelleri group have been mistaken for Russula cessans in the past. |Russula pseudotsugarum has probably been recorded as Russula lilacea in the Pacific Northwest based on Grund(2) (see the account under that species), but R. lilacea may not occur in the Pacific Northwest (Hyde(2)). Russula lilacea has a whitish spore deposit (Crawshay A-B) and favours hardwoods but Grund identified as Russula lilacea specimens that had darker spore deposits (Crawshay C), in low elevation conifer forests. Ben Woo apparently went along with the identification "Grund found it common in conifer woods at low elevations around Puget Sound" but listed the spore deposit as Crawshay A-B (as in literature). Later workers were surprised not to find such a common species with white spores. This cautionary tale has a hint of humor, but there was still one wrinkle to be ironed out. There is a collection by Ben Woo from Washington at the University of Washington labelled as Russula lilacea "keyed out to R. lilacea" (with conifer habitat) and marked clearly spore print A. |The description is derived from Hyde(2).
Russula pseudotsugarum was described from WA, but samples with identical sequences occurred in BC, OR, CA, and Mexico, (Hyde(2)).
Gills: adnate; normally spaced (about 1 gill per mm, presumably at cap margin), sometimes with an occasional subgill or bifurcation; "becoming distinctly yellowish"
Stem: "variable in length, and both distinctly longer or shorter than the cap diameter, slender to distinctly inflated, often also bent in its lower part", equal or more often widening downward; white
Taste: "mild in gills and flesh"
Microscopic spores: spores (6.3)8.1-8.2(10.6) x (4.7)6.3-6.4(8.1) microns, broadly elliptic, "ornamentation (sub)reticulate, with amyloid warts", (0.2)0.6(1) micron high, "fused in short crests or with thin interconnections", "suprahilar spot present as a distinct amyloid patch"; basidia 4-spored, (23)32-44(56) x (9)10-12(13.5) microns, stout and slightly clavate; hymenial cystidia 60-65 x 9-11 microns, "clavate to fusiform, thin-walled"; clamp connections absent
Spore deposit: cream to yellow (about 25% Crawshay D-E, about 75% Crawshay F-G)
Habitat / Range
Pseudotsuga menziesii (Douglas-fir) was present at every collection site, but other conifers usually present as well
Similar Species
Russula zelleri was most often reported with Picea sitchensis (Sitka Spruce) or Picea engelmannii (Engelmann Spruce), although sometimes in mixtures with Abies lasiocarpa (Alpine Fir) or Pinus contorta (Lodgepole Pine). R. zelleri caps "were more likely to be brownish-greenish-yellowish". When R. zelleri caps were darker, "they were more pinkish-brown to vinaceous or even purplish". When darker, R. zelleri caps "had a mottled center with paler yellowish-tan spots". "Standard errors of the means of spore lengths across individual collections" of R. zelleri, R. pseudotsugarum, and R. obscurozelleri overlapped "and so spore measurements cannot be used for identification of individual collections". However the average spore length for R. zelleri was 8.9 microns, while the average spore length of R. pseudotsugarum was 8.1 microns and for R. obscurozelleri, 7.7 microns. (Hyde(2)). The described cap colors of Russula obscurozelleri do not include the greenish or distinctly brown tones mentioned in the description of cap colors for R. pseudotsugarum.