Stropharia ambigua
questionable stropharia
Strophariaceae

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

Introduction to the Macrofungi

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Map

E-Flora BC Static Map

Distribution of Stropharia ambigua
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Species Information

Summary:
Features include a viscid, smooth, yellow cap, white veil remnants hanging from cap margin, white to gray to purplish black gills, and AN off-white stem that has a fleeting ring and white scales on its lower part. It is very common on the Pacific coast (Smith(15)).
Cap:
3-15cm across, obtuse to convex, becoming flat or even uplifted when old; yellow to yellowish brown to yellowish buff, tawny, or sometimes nearly white; viscid or slimy when moist, smooth, "margin hung with cottony white veil remnants", (Arora), 3-8(10)cm across, obtuse to convex when young with inrolled margin, becoming broadly convex to flat when old, rarely slightly umbonate; deep dull yellow to dull yellowish brown to nearly amber when young, gradually becoming pale yellow, sterile caps usually very pale yellow; "viscid, at first decorated with superficial white floccose scales at least near and along the margin", becoming bald, (Smith)
Flesh:
thick, soft; white, (Arora), thick, fairly firm, tapered abruptly near margin; white to whitish, (Smith)
Gills:
"typically adnate but sometimes seceding", close; pale gray, gradually darkening to purplish gray or purplish black, (Arora), "bluntly adnate, often developing a decurrent tooth and sometimes adnexed", close, moderately broad (0.5cm broad), gradually tapered to cap margin; "white when young but soon grayish and finally dark purplish brown", gills finally becoming bright yellow in sterile forms, edges remaining white in sterile forms; edges even, (Smith)
Stem:
6-18cm x 0.5-2cm, more or less equal, often long, stuffed or hollow; "silky and white above the veil", clothed with dry, soft, delicate, cottony white scales in lower part (but these sometimes wearing off), often yellowish toward base when old, "base often with white mycelial threads attached", (Arora), 8-15(20)cm x 1-1.5cm, equal or narrowly club-shaped at base, fleshy, stuffed with white pith; white, when old "dull grayish to yellowish but not discoloring to tawny or ferruginous"; striate over apical part, lower part often floccose from veil remnants or scantily white-fibrillose up to the ragged and torn white floccose ring, soon bald overall; numerous white rhizomorphs surrounding the base, (Smith)
Veil:
"soft, white, cottony, leaving shreds or strands on cap margin and sometimes a superior ring or ragged zone" on the stem (Arora)
Odor:
not distinctive (Phillips), none or earthy (Smith)
Taste:
not distinctive (Phillips), faint and sometimes like raw potatoes (Smith)
Microscopic spores:
spores 11-14 x 6-7.5 microns, elliptic, smooth, chrysocystidia present on gills, (Arora), spores 11-14 x 6-7.5 microns, elliptic, smooth, with apical germ pore and appearing truncate; basidia 4-spored, 34-38 x 8-10 microns, projecting when producing spores; pleurocystidia embedded in hymenium and inconspicuous, 32-64 x 8-12 microns, often arising in gill trama, "broadly fusoid with pointed apices, with a highly refractive content when revived in KOH", cheilocystidia "abundant, subventricose-capitate to cylindric or clavate, the apex rounded and usually as broad or broader than the midportion", colorless in KOH; cap trama with a gelatinous pellicle of narrow hyphae 3-5 microns wide, "below it a compact area of brownish hyphae (revived in KOH), the remainder loosely floccose, hypoderm not differentiated except by the darker color of the hyphae", (Smith)
Spore deposit:
dark purplish to nearly black (Arora), brownish purple (Phillips), purple-brown (Smith)
Notes:
It is reported specifically from BC (Bandoni). The University of British Columbia has collections from BC and WA, and the University of Washington has collections from WA, OR, and AK. It is reported from ID by Andrew Parker, pers. comm. Smith(15) gives a range that includes CA.
EDIBILITY
unknown (Arora, Phillips)

Habitat and Range

SIMILAR SPECIES
Leratiomyces riparius 1) is slightly smaller and slimmer (stem less than 1cm thick), 2) has a thinner more kleenex-like veil that often leaves remnants on the cap near the margin rather than dangling from the margin itself, 3) has a stem that is not nearly as shaggy, and 4) has a cap that is more likely to be slightly umbonate, (Arora). Stropharia hornemannii has a duller (browner or grayer) cap, and a veil that forms a prominent well-developed ring rather than leaving copious strands on the cap margin, (Arora). S. hornemannii "differs in having a cinnamon-gray to dull brown to purplish brown cap and consistently persistent ring, and in being somewhat stockier and less elegant", (Trudell). See also SIMILAR section of Stropharia coronilla.
Habitat
single to scattered or in groups "in rich humus, usually under conifers, but also with alder and other hardwoods", (Arora), usually gregarious "on humus in coniferous forests or in river valleys under alder", fall or sometimes spring, (Smith), large fruitings can occur among wood chips (Trudell)