Amanita rubescens group
blushing amanita
Amanitaceae

Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.

Introduction to the Macrofungi

Photograph

© Michael Beug     (Photo ID #15299)


Map

E-Flora BC Static Map

Distribution of Amanita rubescens group
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Species Information

Summary:
Subgenus Validae. Features include whitish to red-brown color, reddish staining reaction, warty cap that is slightly viscid or dry, skirt-like ring, and indistinct scaly volva. |According to D. Miller, we have from the Pacific Northwest collections that are quite close to Amanita rubescens. For instance three BC specimens were 1 base pair different from a recognized A. rubescens sequence and a fourth 2 base pairs away. Note that the newly described Indian species Amanita orsonii is 3 base pairs away, so the PNW material does appear to be Amanita rubescens. (D. Miller, pers. comm.). |The descriptions here are derived from Bessette(2) who lists it as very common for Northeastern North America (from Tulloss(2) this would be taken to be var. alba), and from Breitenbach(4), presumably representing var. rubescens of Europe. |Members of the group are rare in the Pacific Northwest.
Cap:
4-20cm across, convex to flat; "bronze with brown or red tints"; typically smooth and dry, margin non-striate to faintly striate, "with numerous randomly arranged tan to reddish tan floccose warts", (Bessette), var. alba often has a distinct umbo (Tulloss), 5-12(15)cm across, hemispheric becoming convex to flat; sometimes pale ocher when young, soon ocher brown to reddish brown; entirely or partly covered with light gray to reddish gray, usually concentric, often wart-like veil remnants that can be wiped off, "cuticle peelable, margin smooth, acute", (Breitenbach)
Flesh:
thick; white, rather slowly bruising reddish, (Bessette), thin; white (brownish to reddish under cap surface), "usually turning reddish when cut or where eaten", (Breitenbach)
Gills:
free or very finely attached, crowded, broad; "white, often with slight reddish discolorations", with abundant truncate to subattenuate subgills, (Bessette), var. alba has no squarely truncate subgills, (Tulloss), finely adnexed to free, 110-122 reaching stem, 3 subgills between each pair of gills, gills broad; "white, wine-reddish when old and where eaten"; edges smooth, (Breitenbach)
Stem:
7-20cm x 0.7-4cm, widening slightly downward, solid to stuffed; "white to pale tan, slowly bruising reddish"; "smooth to slightly floccose or fibrous", (Bessette), 8-15cm x 1.2-2.5cm, tapered toward top, base bulbous, stem solid, hollow when old; whitish to reddish brown; appressed-tomentose to finely squarrose, striate to smooth, (Breitenbach), VOLVA universal veil forming indistinct rings of floccose tissue, (Bessette), base zoned (Breitenbach)
Veil:
ring thin, membranous, superior, pendant, white to pale tan, often torn, (Bessette), ring membranous, pendant, white, upper surface striate, (Breitenbach)
Odor:
not distinctive (Bessette), almost none (Breitenbach)
Taste:
mild, rarely bitterish, insipid, faintly nutty (Breitenbach)
Microscopic spores:
spores 7-9 x 5-7 microns, elliptic, smooth, amyloid, colorless, thin-walled, (Bessette), spores (6.5) 7.0-9.8 (10.5) x (4.5)5.0-7.0(8.5) microns, (Tulloss for var. alba), spores 8-11.4 x 4.7-6.5 microns, cylindric - pip-shaped, smooth, colorless; basidia 4-spored, 38-44 x 10-12 microns, clavate, without basal clamps; pleurocystidia not seen, cheilocystidia 20-30 x 10-20 microns, clavate to vesicular; cap cuticle of periclinal hyphae 1.5-3.5 microns across, gelatinized, septa without clamps, (Breitenbach)
Spore deposit:
white (Bessette), whitish (Breitenbach)
Notes:
Paul Kroeger reports A. rubescens from BC [with knowledge of Amanita novinupta] (collection at University of British Columbia). Breitenbach(4) give the distribution of A. rubescens as North America, Europe, Asia, and North Africa.
EDIBILITY
edible [cooked] but not recommended [too many lookalikes], (Bessette), one or more members of the Amanita rubescens group contain an acidic protein that can destroy red blood cells - it goes by the name rubescenslysin, (Seeger)

Habitat and Range

SIMILAR SPECIES
Amanita novinupta 1) has a universal veil that sometimes appears at soft, cottony patches on the cap, 2) has some squarely truncate subgills, 3) has larger and proportionately narrower spores (than var. alba but not var. rubescens which has similar sized spores to A. novinupta), and 4) differs microscopically in other ways (see A. novinupta), (Tulloss)
Habitat
scattered to grouped, on ground in mixed woods or under trees in grassy areas, July to October, (Bessette), single to gregarious or grouped in hardwood and coniferous forest, late spring to fall, (Breitenbach), spring, summer, fall