Trial field key to the species of VOLVARIELLA in the Pacific Northwest

Prepared for the Pacific Northwest Key Council
By Eugene Butler (Snohomish County Mycological Society;
Southwest Washington Mycological Society) 2012
Copyright © 2012 Pacific Northwest Key Council
Photo copyright held by each photographer
Do not copy photos without permission

INTRODUCTION

The genus Volvariella includes non-mycorrhizal agaric fungi with the following combination of characters: free gills, a pink or pinkish brown spore deposit and a fleshy-fibrous stalk with a distinct volva at the base. Gill tissue convergent. No partial veil. Spores are smooth and usually elliptical. The species are not common and the edibility of only some is known. Some species could be confused with species of Amanita. Amanita species have a white spore deposit and may have a ring on the stalk.

KEY TO SPECIES

1a Growing terrestrially on decayed wood, soil, humus or other gilled mushroom

................................................................................2

1b Growing on living or dead trees

................................................................................V. bombycina (Schaeff. ex Fr.) Sing.

CAP: 50-200 mm broad, buttons egg-shaped to globe-shaped, expanding to bell-shaped or convex, finally nearly plane; margin more or less fringed, not striate. Surface dry, covered with silky hairs, somewhat scaly in age. Color white, yellowish or dirty centrally. Flesh thin, soft, white. Odor slight, taste mild. GILLS: free, crowded, broad in center, narrow at both ends (i.e. ventricose), edges torn; white in buttons, becoming flesh color. STEM: 60-200mm long; 10-20mm thick, enlarged downward to base, sometimes bulbous; solid; surface hairless; color white. VOLVA: saccate, usually split into lobes, persistent and thickly membranous, reaching almost to the middle of the stem, whitish externally when young, later ocher, to brown and areolate when old. HABIT: solitary to gregarious. HABITAT: saprophytic in wounds on roots and trunks of living or on dead hardwoods, usually maple but also including magnolia, mango, beech, oak and elm; June-September. SPORES Spores smooth, elliptical, 6.6-10.4 x 4.4-6.7 μ, pinkish brown. Basidia clavate, 20-30 x 8-11 μ, 4-spored. EDIBILITY: edible and choice. REMARKS: A common name for this species is “Ermine Cloak”. As originally described V. bombycina has a white cap and white volva. Species with a cap and/or volva brown or becoming brown have been treated as var. bombycina by many authors. Species with a yellow cap and known from Florida have been recognized as V. bombycina var. flaviceps (Murr.) Shaffer.

Volvariella bombycina Noah Siegel

2a Cap dry

................................................................................3

2b Cap sticky when moist, shiny when dry, white or grayish brown

................................................................................V. gloiocephala (DC: Fr.) Boekhout & Enderle

CAP: 50-150 mm broad, buttons egg-shaped to globe-shaped, expanding to convex or plane with a ± visible umbo. Surface sticky when wet, glabrous, at times bearing patches from the universal veil, edge slightly striate or non-striate. Color white or light grayish yellowish brown or light brownish gray, often darker centrally. Flesh white, brownish under the cuticle, moderately thick centrally, thin toward edge, soft, white. Odor musty to raphanoid, taste mild, faintly raphanoid. GILLS: free, broad in center and narrow at both ends (i.e. ventricose); close to crowded; edges uneven to torn; white in buttons becoming brown-pink to gray-pink. STEM: 90-200 mm long, 8-20 mm thick, equal or enlarging downward with base slightly clavate or sometimes with a bulb up to 30 mm thick. Surface dry, glabrous or downy with base hairy to woolly, becoming longitudinally fibrillose, apex white-powdery. Color whitish when young, later brownish. Flesh solid. VOLVA: shallow to 20-30 mm long, rigid, fragile, edge free and nearly even, split or lobed; color white to light gray; often buried deep in soil, sometimes inconspicuous. HABIT: solitary to scattered or gregarious., sometimes in rather large crowds. HABITAT: cultivated soil—gardens, vacant lots, roadsides, manure, compost, straw heaps, fallow and planted fields—occasionally in the woods in fall, occasionally in the spring. SPORES Spores smooth, elliptical, 11.5-21 x 7-12μ, pinkish brown. Basidia clavate to ventricose, 30-48 x 13-16 μ, 4-spored. EDIBILITY: edible, but of poor quality. REMARKS: This species has been recognized as V. speciosa (Fr.) Sing. with V. gloiocephala (DC ex Fr.) Sing. as a variant; recent studies have shown both species grow from the same mycelium and are therefore the same, the brown form fruiting following the white form. Gloiocephala is the older name and therefore the one conserved. The cap of V. pusilla (7b) may be sticky when young, but its fruiting body is much smaller. The young stages of V. gloiocephala and the deadly Amanita virosa and related species may look similar but those species have a ring and have a white spore print. Due to recent DNA studies, Justo, A. et al. now propose that volvariellas with spores over 11 μ long and with a gelatinous matrix in the cap be transferred to a new genus, Volvopluteus.

Volvariella gloiocephala Kit Scates Barnhart

3a (2a) Cap smoky gray or grayish yellow brown

................................................................................4

3b Cap white

................................................................................5

4a (3a) Cap large, 50-100 mm, smoky gray, volva large

................................................................................V. volvacea (Bull. ex Fr.) Sing.

CAP : 50-100 mm broad, egg-shaped when young, expanding to bell-shaped or convex, at times subumbonate or depressed centrally; dry, streaked with dark fibrils, often radially cracked. Color smoky to grayish brown, blackish brown centrally. Flesh 3-5 mm thick centrally, tapering ± evenly to thin at edge, soft, white. Odor meaty-aromatic, taste mild.
GILLS: free, close, broad, edges minutely fringed, white becoming deep flesh color.
STEM: 45-140 mm x 3-20 mm, round, subequal or enlarging slightly to a subbulbous base. Flesh stuffed becoming hollow, innately fibrillose. Color off-white to dull brown.
VOLVA: large, cottony, brownish.
HABIT: solitary to gregarious.
HABITAT: on soil or compost piles, often in hothouses and cellars, spring and summer.
EDIBILITY: edible and choice.
SPORES: smooth, elliptical, 7-10.5 x 4.5-7 μ, pinkish brown. Basidia 20-44 x 7-11μ, clavate, 4-spored.
REMARKS: Known as the “paddy straw” mushroom, this species is widely cultivated commercially for use in soups, stir fry and other dishes.

4b Cap smaller, 20-60mm, gray to grayish yellow brown, volva small, not believed to be present west of the Rocky Mountains

................................................................................V. taylorii (Berk. & Broome) Sing.

CAP: CAP : 20-60 mm broad, obtusely conic to convex, often subumbonate, at times expanding to almost plane. Surface dry, prominently fibrillose, edge non-striate but often torn. Color gray with grayish yellow brown areas. Flesh thin, 1 mm or less thick, white. Odor and taste slight or none.
GILLS: free, close to subdistant, moderately broad to 4-7 mm broad centrally, narrow at ends, with minutely fringed edges, whitish becoming salmon colored.
STEM: 35-65 mm x 3-7 mm enlarging to subbulbous base, round, solid, white.
VOLVA: small (up to 10 mm), cup-shaped with 3-5 lobes, color date-brown or grayish yellow brown externally, fading to whitish, white internally.
HABIT: solitary to gregarious.
HABITAT: humus, compost, trash heaps and decayed hardwoods, summer.
EDIBILITY: edible.
SPORES: 5.6-8.7 x 4.1-6 μ, elliptic, smooth, dark rose. Basidia 23-40 x 6-10 μ, clavate, usually 4-spored, rarely 1-, 2-, or 3-spored.
REMARKS: This species differs from V. volvacea in its smaller stature, paler cap color, and smaller spores and cystidia. It is not believed to be present west of the Rocky Mountains.

5a (3b) Stem pubescent

................................................................................6

5b Stem glabrous or with appressed longitudinal fibrils

................................................................................7

6a Volva white, inconspicuous

................................................................................V. hypopithys (Fr.) Shaffer

CAP : 20-60 mm broad, bell-shaped or convex becoming nearly plane with an obtuse umbo in age. Surface dry, with fine silky hairs that sometimes form small scales, edge usually fringed with long, silky white hairs and not striate or only faintly so. Color pure white or tinged yellowish centrally, sometimes discoloring overall in old age. Flesh thin, soft, white. Odor and taste slight to none.
GILLS: free, close to crowded, narrow, edge minutely fringed, whitish becoming flesh colored.
STEM: 20-80 mm long, 2-5 mm thick, slightly tapered toward apex, base ± bulbous, solid becoming hollow. Surface densely pubescent to long hairy but base hairless. Color white.
VOLVA: membranous, small, often inconspicuous or barely visible at base of stem; white, usually lobed.
HABIT: solitary or in small groups.
HABITAT: in soft or hard woodland humus, summer and early fall.
EDIBILITY: edible.
SPORES: spores 6-8.5 x 3.5-6 μ, broadly elliptical, smooth, pink-brown. Basidia cylindric-clavate 21-25 x 7-8 μ, 4-spored, rarely 2-spored.

6b Volva stained ochre to brownish, prominent

................................................................................V. smithii Shaffer

CAP: 20-50 mm broad, obtusely conic to convex or plane. Surface dry, appressed fibrillose and cracked along non-striate edge. Color white, often tinged buff to pinkish-buff centrally. Flesh soft, white. Taste mild, odor slightly aromatic.
GILLS: free, close, broad, edges slightly uneven, white, becoming pink.
STEM: 30-50 mm long, 3-7 mm thick, equal or enlarged at base, white, covered with fine white hairs (i.e. pubescent).
VOLVA: large, prominent, saclike, usually lobed, outside with matted fibrils; color yellow-ochre to brownish.
HABIT: solitary or in small groups.
HABITAT: on soil or humus in mixed woods, September-October.
EDIBILITY: unknown.
SPORES: 4.7-7 x 3.1-3.9 μ, elliptical, smooth. Basidia 20-27 x 6-8 μ, clavate, 4-spored.

7a (5b) Cap 25-80 mm, margin not striate, cap surface dry, growth on other, not necessarily visible, rotting mushrooms, widely distributed though not common

................................................................................V. surrecta (Fr.) (Knapp) Sing.

CAP : 25-80 mm broad, buttons egg-shaped, expanding to bell-shaped (i.e. campanulate) or convex, finally nearly plane, broadly umbonate or not, margin not striate. Surface dry, silky, appressed radially fibrillose. Color white to light gray. Flesh moderately thick, soft, white; odor slight, taste mild.
GILLS: free, close; moderately broad centrally, narrower at both ends (i.e. subventricose); margins cottony; white in buttons becoming deep flesh pink.
STEM: 40-90 mm long, 4-12 mm thick, equal or enlarged at base; solid when young becoming hollow in age. Surface appressed longitudinally fibrillose, with powdered appearance at top; color white to light gray.
VOLVA: 13-25 mm high, 6-13 mm broad, free edge lobed or nearly even; white.
HABIT: solitary to clustered.
HABITAT: Parasitic on rotting fruit bodies of gilled Clitocybe or Tricholoma mushrooms (usually Clitocybe nebularis) which may be no longer visible; on ground in woods and meadows; late summer-fall.
EDIBILITY: unknown.
SPORES: Spores smooth, elliptical, 5.5-7.5 x 3.5-7 μ, reddish-brown. Basidia cylindric-clavate, 20-30 x 6-8 μ, 4-spored.

7b Cap 5-30 mm, margin striate in age and cap may be sticky when young, growth in damp locations, along streams, gardens and lawns, not believed to be present west of the Rocky Mountains

................................................................................V. pusilla (Fr.) Sing.

CAP: 5-30 mm broad, button egg-shaped expanding to rounded bell-shaped or convex, eventually nearly plane, sometimes weakly umbonate. Surface slightly sticky at first, soon dry, with pressed down fibrils, edge striate in age. Color white, occasionally tinged with gray, especially centrally. Flesh thin, up to 1.5 mm thick. Odor and taste slight to none.
GILLS: free, close to subdistant, edge entire, moderately broad (up to 4 mm), white becoming pink.
STEM: 10-50 mm long, 1-5 mm thick, equal or tapering to apex, round. Surface hairless but with innate fibrils. Flesh solid becoming hollow. Color white, at times tinged with gray.
VOLVA: persistent, deep, lobed, membranous, color white becoming grayish.
HABIT: solitary to gregarious.
HABITAT: in moist damp locations, along streams, gardens and lawns, summer, fall.
EDIBILITY: unknown.
SPORES: Spores 5.5-8 x 4-5.7 μ, elliptic, smooth, thick-walled, pinkish brown. Basidia cylindric clavate, 25-32 x 7-8.5 μ, 4-, rarely 2-spored.
REMARKS: A common name for this species is “Little Ermine Cloak.” This species is not believed to be present west of the Rocky Mountains.

GLOSSARY

Areolate: a space marked out and separated from other areas by cracks much like dried mud

Campanulate: bell-shaped

Fibrillose: of a surface having hairy filaments which are thin and threadlike, arranged more or less parallel to one another, distinguished from “tomentose”

Glabrous: lacking scales or hairs; smooth

Pubescent: provided with a covering of short, soft, downy hairs

Raphanoid: odor or taste resembling radish

Saccate: a volva that remains as a sac, cup, or sheath

Umbonate: with a raised conical to convex knob or mound on the center

Ventricose: Broad in the middle

REFERENCES

1. Arora, David. 1986. Mushrooms Demystified. Ten Speed Press, California. pp258-62.
2. Breitenbach, J. and F Kränzlin. 1995. Fungi of Switzerland, Volume 4. Sticher Printing AG, Lucerne. pp127-33.
3. Courtecuisse, R. & B. Duhem. English ed. 1995. Mushrooms & Toadstools of Britain & Europe. Harper/Collins. p288.
4. Glick, Phyllis G. 1979. The Mushroom Trail Guide. Holt, Rinehart and Winston, New York. pp92-3.
5. Groves, J.W. 1962. Edible and Poisonous Mushrooms of Canada. Canada Dept. of Agriculture, Ottawa. pp167-8.
6. Justo A. et al. 2011. "Phylogeny of the Pluteaceae (Agaricales, Basidiomycota): taxonomy and character evolution." Fungal Biol. 115(1): 1-20.
7. Lincoff, Gary H. 1981. The Audubon Society Field Guide to North American Mushrooms. Alfred A. Knopf, New York. pp677-9.
8. McKenny, Margaret. 1971 ed. rev. & enlarged by D. E. Stuntz. The Savory Wild Mushroom Univ. of Wash., Seattle. pp110-11.
9. Miller Jr., Orson K. & Hope Miller. 2006. North American Mushrooms. Globe Pequot Press, Connecticut. pp205-7.
10. Moser, Meinhard. 1983. Keys to Agarics and Boleti, Eng. Translation of 4th ed. Whitefriars Press Ltd., Tonbridge. pp 216-7.
11. Orton, P. D. 1986. British Fungus Flora Agarics and Boleti, vol. 4 Pluteaceae: Pluteus & Volvariella. Royal Botanic Garden, Edinburgh. pp. 61-74.
12. Phillips, Roger. 1981. Mushrooms and Other Fungi of Great Britain & Europe. Pan Books, London. p112.
13. Shaffer, Robert L. 1957. "Volvariella in North America." Mycologia 49: 545-579.
14. Shaffer, Robert L. 1962. "Synonyms, new combinations, and new species in Volvariella." Mycologia 54: 563-72.
15. Smith, A. H., H. V. Smith and Nancy S. Weber. 1979. How to know the Gilled Mushrooms. Wm. C. Brown Company, Iowa. pp191-4.
16. Snell, Walter H. & Esther A. Dick. 1971. A Glossary of Mycology. Harvard University Press.

INDEX

- END -