E-Flora BC: Electronic Atlas of the Flora of British Columbia

Russula fragilis (Pers. ex Fr.) Fr.
fragile Russula

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

Introduction to the Macrofungi

© Rosemary Taylor  Email the photographer   (Photo ID #26491)

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Distribution of Russula fragilis
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Species Information

Russula fragilis is characterized by variable color (most typically dark at center, pinkish toward margin and grayish olive between), fragile texture, white gills, peppery taste and white spore deposit, (Arora). Shaffer says that the color is variable but most commonly some shade or intensity of grayish purple or grayish red to yellowish pink and usually tinged olive to green in places; other features are small size, peppery taste, habitat usually lacking Sphagnum, small to medium spores, and 0-3 septate hyphal ends (pseudocystidia) on cap and stem, (Shaffer(6)). Singer distinguishes a number of forms and a variety: f. emeticella Singer, small, fragile with light red cap, grows on stumps; f. griseoviolacea Britzelm., dirty red cap with shades of grayish violet, in coniferous forests; f. fallax Cke sensu Bres., cap has dark brown or olive green center, often slightly pruinose; f. fumosa Gillet (=gilva Britzelm.), gray cap; f. nivea Cooke, pure white from the beginning, singly in mountain forests with herbal undergrowth; f. violascens Gillet, watery violet cap; f. knautthii Singer, lilac pinkish violet or dark red, with lilac or rusty black center, odor of desiccated coconut, very echinulate spores; f. raoultii Quel., light lemon yellow to lemon white or pale yellow green cap, rare, in grass beneath aspen, oak or beech; and var. salicina Melzer, cap only 2-3cm across, varying in color, very rapidly turning white from margin to center, away from forests beneath willows, (Pilat). Sarnari (1998) synonymizes Russula atropurpurea (Singer) Crawshay and R. atropurpurea var. atropurpurea (Singer) Singer with this taxon (Roberts, C.(2)). The University of British Columbia has collections labeled as this species from BC, AB, NB, and TN. The University of WA has collections labeled as this species from WA, AK, MI, and VT. The species was reported from WA by Grund (type variety and a provisional variety roseolipes with stem washed with rose or pink) and in the broad sense by Trudell(3). It is included by Thiers(3) for CA. Shaffer(6) examined collections from QC, CO, MI, and VT., CHEMICAL REACTIONS stem surface reactions: 10% FeSO4 pale yellowish pink, SV light purplish gray, 2% phenol dark grayish reddish brown, formalin colorless to pale pink, guaiac quickly dark greenish blue, (Shaffer(2)), in Europe guaiac reaction slow and weak, (Shaffer(6)), tan reaction to FeSO4 with cap flesh, purple reaction to SV with cap flesh, (Grund)
2-6cm across, usually depressed in center, "very variable in color, purple, wine, violet, red or pinkish red with center almost black or brown or olive, sometimes with light spots or entirely white"; viscid drying smooth, margin not grooved, cap skin peeling 3/4, (Woo), 2-5cm across, convex becoming flat or depressed; "purplish to pinkish, olive-brown, greenish, or even yellow, or a mixture of these colors", but most often blackish at the center and pinkish or pinkish yellow at margin, with a grayish olive zone in between; viscid when moist, smooth, margin striate when old, (Arora), 2-6.5cm across, when young deeply pulvinate [cushion-shaped] with incurved margin and sometimes a prominent umbo, expanding to flat-convex or flat and then either subumbonate or with a shallowly depressed disc, concave when old; when young dark grayish purple or dark purplish gray, dark grayish red, or grayish reddish brown and sometimes suffused with grayish olive around the center, when mature these same colors remaining centrally, but dark to moderate red, grayish red, moderate to light reddish brown or dark pink to strong yellowish pink marginally, sometimes fading to pale grayish yellow or light grayish olive with or without areas of grayish purple, reddish brown, or yellowish pink; viscid and shiny when moist, bald (minutely velvety under lens), sometimes minutely tuberculate-rugulose centrally, separable 1/2-3/4 of cap radius, becoming striate or tuberculate-striate 0.2-0.6cm from edge inward, (Shaffer(2)), 2-5(7)cm across, depressed in center, margin thin and sharp, rarely blunt; "lilac wine, dark purple, currant red, violet, carmine or pinkish red and in the centre almost black, brown or olive, often with paler spots, but the mushroom may also be pale blue spotted or even white", "the pale parts of the cap are often depressed"; viscid, shiny, sometimes matte when dry, smooth and bald but also granular gibbous, often warted or white pruinose in center, cap skin separable far up cap, (Pilat)
fairly firm; white, (Woo), thin, very fragile; white, (Arora), 0.15-2.5cm at mid-radius, soft-brittle; sometimes tinged with cap color just beneath surface, otherwise white, "unchanging or becoming faintly yellowish when cut", (Shaffer(2)), quite firm but easily wilting; white, even beneath cap cuticle, (Pilat)
narrow; white; with edges finely floccose or crenulate [scalloped], (Woo), "adnate to adnexed or even free, fairly close"; white or creamy white, (Arora), subdecurrent, adnate, or adnexed, sometimes almost free, close to subdistant, equal or unequal with the subgills rare to occasional and of various lengths, gills 0.2-0.6cm broad, elastic, occasionally forking at or near stem, rarely outward, or not forking at all, interveined; yellowish white, unchanging when injured, but sometimes becoming more yellow when old; entire, (Shaffer(2)), European specimens often have serrulate (finely toothed) edges, but this feature not found in North American specimens examined, (Shaffer(6)), quite narrow and attenuated or even slightly decurrent near stem, rounded; pure white, later yellowish; very finely floccose on edges, (Pilat)
white, later faintly yellow, (Woo), 2.5-7cm x 0.5-1.5cm, equal or slightly wider at either end, fragile; whitish; dry, (Arora), 2.5-6cm x 0.5-1.4cm, flared at top or not, otherwise more or less equal or widening to base, solid then stuffed; "white, at times stained light to moderate yellow basally, unchanging or becoming pale gray when injured"; dry to moist, dull, tomentose at the very base, puberulent at top, or bald overall, longitudinally rugulose [wrinkled], (Shaffer(2)), 2-7cm x 0.7-1.5cm, "full and hard, later spongy, soft and fragile, often watery at base when picked, flabby when drying"; always white, later faintly yellow; pubescent pruinose, then bald, often silky, then wrinkled, (Pilat)
pleasant fruity, (Woo), variable (Arora), none, or more usually, of apples or coconut, or even spermatic, (Shaffer(2)), mild or more usually of apples, mint, or coconut, or even spermatic, in Europe of amyl acetate (pear-like), (Shaffer(6)), pleasant frui
very peppery (Woo), peppery (Arora), slightly or moderately peppery, sometimes also with a radish-like component, (Shaffer(2)), slightly to strongly peppery, sometimes also with radish-like component, (Shaffer(6)), sharp stinging, (Pilat)
Microscopic spores:
spores 7.5-9 x 6-8 microns, ornamentation Patterson-Woo type C-2, D-2, (Woo), spores 6-9 x 5-8 microns, broadly elliptic to nearly round, amyloid warts and ridges, (Arora), spores (5.7)6.6-9.0 x (5.0)6.0-7.7 microns, broadly elliptic, broadly ovate or obovate, or nearly round, ornamentation of short ridges and convex to subcylindric or conic warts and spines up to 0.3-1.0(1.6) microns high, these units sometimes aligned or with connectives, often forming a partial or complete reticulum; basidia 4-spored, 24-43 x 7.3-11.3 microns, clavate; hymenial pseudocystidia abundant, arising at various levels in subhymenium or outer edge of trama, projecting up to 30 microns beyond basidioles, 34-85 x 4.5-11.3 microns, "fusiform, fusoid-clavate, or clavate", "often papillate to appendiculate, otherwise subacute to rounded apically", SV+; cap epicutis 62-90 microns thick (subcutis 51-90 microns thick), embedded in a gelatinous matrix, a trichoderm of non-gelatinous to gelatinous connective hyphal ends 1.0-4.5 microns wide "which may contain a grayish purple to moderate red vacuolar pigment and whose apical cells may be subclavate or subfusiform", "also with numerous, subcylindric, subfusiform, or more usually clavate, 0-3-septate, SV+ pseudocystidia" which are 23-96(260) x 3.4-10.2 microns and arise in epicutis or subcutis, (Shaffer(2)), spores 7-9 x 6-7 microns, round elliptic, minutely warted or finely echinulate, often completely reticulate to ridged, (Pilat)
Spore deposit:
white to cream, Crawshay A-B, (Woo), whitish (Arora), yellowish white, Romagnesi Ib or darker, but not as dark as IIa, (Shaffer(2)), usually yellowish white, rarely almost white (almost Ia), (Shaffer(6)), whitish to faintly yellowish (Pilat)

Habitat / Range

conifer forests in moss or on decayed wood, (Woo), single, scattered, or in groups in woods, especially conifers, (Arora), single to scattered on humus or rotten wood in coniferous and mixed woods, (Shaffer(2)), in forests of all kinds, but particularly in damp and shady coniferous forests on ground, in moss and needles or on very rotten tree stumps, (Pilat), fall and winter (Buczacki)

Taxonomic and Nomenclatural Links

Additional Range and Status Information Links


not recommended (Arora)

Additional Photo Sources

Related Databases

Species References

Shaffer(2), Shaffer(6), Pilat(1), Arora(1)*, Phillips(1)*, Lincoff(2)*, Schalkwijk-Barendsen(1)*, Kibby(1)*, Courtecuisse(1)*, Barron(1)*, Woo(1), Thiers(3), Miller(14)*, Grund(2), Roberts, C.(2), Trudell(4)*, Trudell(3), Buczacki(1)*

References for the fungi

General References