Notes on MELANOLEUCA in the Pacific Northwest

Prepared for the Pacific Northwest Key Council
By Ian Gibson, South Vancouver Island Mycological Society
Copyright © 2008 Pacific Northwest Key Council
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INTRODUCTION

The genus Melanoleuca has not been systematically studied in the Pacific Northwest. Gillman and Miller (1977) gave an account of four species reported from the Pacific Northwest: Melanoleuca graminicola (including M. angelesiana as a synonym), M. evenosa, M. melaleuca, and M. microspora. Three other species are considered here: M. verrucipes (a distinctive species reported by several observers), M. cognata (probably a complex of species but reported by several observers), M. eccentrica (found at least in Washington but apparently rare). Other species undoubtedly occur in the Pacific Northwest.

 

MELANOLEUCA Pat.

FRUIT BODIES small to medium-sized mushrooms that grow on the ground, usually blackish to whitish or shades of brown, less often yellowish. CAP broadly convex to flat, often umbonate, often hygrophanous, usually smooth. GILLS usually adnate or notched, spacing close or crowded, usually white. STIPE usually rather slender compared with cap width, typically rather stiff, often longitudinally fibrous-striate. VEIL and VOLVA absent. SPORE DEPOSIT white or cream, rarely buff. MICROSTRUCTURES spores roughened or with minute warts, amyloid, cheilocystidia and pleurocystidia present (usually with pointed apex that has incrustations near tip) or absent, clamp connections absent.

 

Pluteus species may also have wide, nearly flat caps with slender stipes and crowded gills, but gills are free, spore deposit is pinkish brown and many grow on wood.

With the exception of Melanoleuca verrucipes, these species should be identified microscopically.

 

KEY TO INCLUDED SPECIES

1a White to cream cap and white stipe with dark scales reminiscent of the scabers on the stipe of Leccinum

1b Color different or scales absent

2a Pleurocystidia present, obvious, clearly protruding beyond basidia, cheilocystidia present

2b Pleurocystidia absent, or rare, inconspicuous and barely protruding beyond basidia, (cheilocystidia also absent in species covered here)

3a Gills tan, ocher, creamy ocher, or pale pinkish cinnamon, spore deposit deep creamy yellow

3b Gills typically whitish, sometimes with slight yellow or pinkish tinge (may stain brown or ocher when old), spore deposit white to cream

4a Cap brown to dark brown, slender stature, in grassy areas or woods, distribution widespread

4b Cap white to dark brown, robust stature, most often in mountain areas in conifer woods or subalpine meadows after snow melt, cap often becoming areolate when old

5a (2b) Stipe distinctly eccentric (off-center), cap pale yellow, odor and taste somewhat spermatic as in some Inocybe, rarely collected, spores 7-8 x 4-5 um

5b Stipe central, cap various colors, odor not somewhat spermatic, spores shorter or wider

6a Spores 6-7(8) x 4-5.5(6) um

6b Spores 7-9 x 5-6 um

 

DESCRIPTIONS

Melanoleuca angelesiana A.H. Sm. (= M. graminicola (Velen.) Kühner & Maire sensu O.K. Mill.)

CAP (2)3-7(11) cm across, with or without umbo, sometimes depressed in center or around umbo; dark brown to dark gray brown to dark copper brown to dull olive brown, fading to bright brown; moist to subviscid, bald or occasionally with appressed fine scales. GILLS adnate to notched or slightly adnexed, crowded, moderately broad; white to pallid, cream, buff, or pale gray, some with pinkish tinge when old, the edges staining sordid brownish where bruised. STIPE 5-6 cm x 0.3-1.2(1.5) cm, flared slightly at top and base, central to slightly off-center; white at top and darkening to brown in lower part or colored as cap (or paler) overall; longitudinally fibrous-striate, bald or with scattered fibrils or finely pubescent, dry to moist. ODOR mild. TASTE mild to somewhat disagreeable. HABITAT single to gregarious, occasionally cespitose on ground, near melting snowbanks under conifers, late May to early August, at high elevations. DISTRIBUTION at least WA, OR, ID. SPORE DEPOSIT white to buff or cream. MICROSTRUCTURES spores 7-8(9) x 4.5-5(6) um (Smith), spores (7.5)8-9(10) x 5-6 um (Gillman and Miller), elliptic, covered with strongly amyloid minute warts, with a subhilar depression; pleurocystidia and cheilocystidia none. REMARKS Melanoleuca angelesiana A.H. Sm. Mycologia 36: 252. 1944 is given as a synonym by Gillman and Miller, but according to Bessette (1995), further study of M. graminicola as described by Velenovský in 1920 “has lead to the conclusion that it is not the high elevation species as indicated by Gillman and Miller (1977) but a small European species in grassy habitats.” M. stridula (Fr.) Singer sensu Métrod and sensu Kühner also has a similar description in Breitenbach & Kränzlin (1991), who give M. graminicola Vel. sensu Favre as a synonym. Here we account for similar species by the term Melanoleuca angelesiana group. It should be noted that Bon synonymized M. graminicola with M. melaleuca (Pers.: Fr.) Murrill sensu Kühner (who regarded the latter as a species without cystidia).Melanoleuca angelesiana group
Melanoleuca angelesiana group
Michael Beug

Melanoleuca cognata (Fr.) Konrad & Maubl.

CAP (5)7-13 cm across, broadly convex to flat, usually with broad umbo, sometimes becoming slightly depressed; brown to ocher-brown or gray brown, fading when old; smooth. GILLS attached (usually notched), crowded, becoming broad; whitish to cream, creamy ocher, deep ocher, tan, or pale pinkish cinnamon. STIPE 6-12 cm x 1-2 cm, equal or widened at base; colored like cap or paler, the base sometimes brownish-stained; longitudinally lined or twisted-striate. ODOR variously described as slightly sweet, flowery, slightly fruity, floury-rancid, or peculiar. HABITAT single, scattered or in small groups on ground in mixed woods and under conifers, spring to early fall. DISTRIBUTION reported by Pacific Northwest Key Council members from at least BC and WA, and Arora says it is fairly frequent in the southern Rocky Mountains and Southwest. SPORE DEPOSIT creamy or yellowish. MICROSTRUCTURES spores 7-10 x 4.5-6 um, elliptic, finely warted, amyloid; cystidia abundant on gills; pleurocystidia and cheilocystidia variously described. REMARKS probably a complex of species.Melanoleuca cognata
Melanoleuca cognata
Steve Trudell

Melanoleuca eccentrica A.H. Sm. Mycologia 36: 251. 1944

CAP 4-7 cm across, becoming flat-umbonate; pale buff to pale yellowish; moist, bald, opaque, margin cottony when young. GILLS adnexed, crowded, narrow; pallid. STIPE 4-5 cm x 0.9-1.0 cm, off-center, equal or enlarged in lower part; pinkish gray; appressed fibrillose-striate, bald. ODOR and TASTE somewhat spermatic and disagreeable (Inocybe-like). HABITAT under conifers in Olympic mountains, October. DISTRIBUTION found at least WA, apparently rare. SPORE DEPOSIT presumably whitish. MICROSTRUCTURES spores 7-8 x 4-5 um, elliptic, covered with minute strongly amyloid warts; pleurocystidia and cheilocystidia none.

Melanoleuca evenosa (Sacc.) Konrad

CAP 9-14 cm across, convex to flat, or curved up when old; mostly grayish ochraceous but often with a dark brown disc, may be dark brown when young and may be dingy brown when old [but see remarks below]; dry, bald, areolate to rimose when old. GILLS notched, close, very broad; almost white with a pinkish hue. STIPE 6-10 cm x 1.5-3 cm, robust, thick, equal; dull white; dry, sometimes minutely pubescent. ODOR and TASTE not distinctive. HABITAT single or usually in groups on ground in conifer forests or subalpine meadows in the Rocky Mountains, usually above 3000 feet, June to August, but reported by R. Sieger from sea level in WA. DISTRIBUTION at least Idaho (also AK, MT, WY). SPORE DEPOSIT white. MICROSTRUCTURES spores 7.5-9.5 x 4.5-6 um, elliptic, with amyloid warts; pleurocystidia and cheilocystidia frequent, 35-65 x 10-13 um, lageniform or fusiform, apex obtuse to acuminate, often covered with crystals, thin-walled. REMARKS The concept above is from Gillman and Miller (1977). Miller & Miller (2006) says this species has white to cream cap, and McKnight & McKnight (1987) says it has orange-yellow colors, sometimes with no trace of brown or with center flushed with brown. Arora (1986) mentions that gills in the Melanoleuca evenosa group are usually notched or adnexed, and they are white but may stain brown or ocher, and mentions that the stipe is white with brownish or cap-colored fibrils and is usually dandruffy or minutely scaly in upper part, sometimes dandruffy throughout, and spores are 8-11 x 4-5 um.Melanoleuca evenosa group
Melanoleuca evenosa group
Michael Beug

Melanoleuca melaleuca (Fr.) Murrill sensu Gillman & Miller

CAP 2-8 cm across, convex then flat to concave, sometimes with umbo; hygrophanous, gray brown, pale brown to brown, dark brown or dark yellow-brown; bald, dry, moist or viscid. GILLS usually notched, close to crowded, narrow; white, tan, pale pinkish buff, or salmon. STIPE 3.5-13 cm x 0.3-1.8 cm, central to slightly off-center, equal above a bulbous base; white at top, below that paler than cap; with longitudinal, colorless to dark fibrils, granular at apex. ODOR mild. TASTE mild to somewhat unpleasant. HABITAT single to several on ground in meadows, in deciduous or conifer woods, June to September. DISTRIBUTION uncertain because of different interpretations of the species, despite many reports. Gillman and Miller examined collections from ID, AB, YT, AK, MT, VA, and Europe, and Arora reports it common in his area of CA. SPORE DEPOSIT white or cream. MICROSTRUCTURES spores 6.5-9(10) x 4.5-6 um, ellipsoid, verrucose with suprahilar plage, warts amyloid; pleurocystidia and cheilocystidia frequent, 30-70(90) x 7-15(20) um, lageniform to fusiform, apex acuminate to obtuse, occasionally 2-celled, thin-walled or apex sometimes somewhat thick-walled and often covered with crystals. REMARKS Confusion has resulted from descriptions under this name specifying that no cystidia are present (Kühner for example). Here we are following Gillman and Miller. Gillman and Miller say that is distinguished by its lageniform to fusiform pleurocystidia and cheilocystidia (never broadly clavate) along with the lack of gray or gray-brown coloration in cap, but then include gray-brown as one of the options in their color description.Melanoleuca melaleuca
Melanoleuca melaleuca
Kit Scates Barnhart

Melanoleuca microspora L.S. Gillman & O.K. Mill.

CAP 2-4.5 cm across, flat with downcurved margin, when old with shallow depression or low umbo; tan to brown; dry to moist with a waxy texture, bald, smooth. GILLS adnate, notched, close, narrow to broad when old, several tiers of subgills; white to bright tan. STIPE 3.5-4.5 cm x 0.2-0.45 cm, central to slightly off-center, equal, widening slightly to a small bulbous base; colored as cap or tinted orange, sometimes darkening over base; dry, with shallow longitudinal striations. HABITAT single or in small groups on moss-covered ground, usually on very moist stream banks in mixed conifer woods, does occur in mountain areas. DISTRIBUTION at least Idaho, AK, MT. SPORE DEPOSIT presumably whitish. MICROSTRUCTURES spores 6-7(8) x 4-5.5(6) um, nearly round to short elliptic, with amyloid warts, colorless in KOH; pleurocystidia and cheilocystidia absent.

Melanoleuca verrucipes (Fr.) Singer

CAP 4-11 cm across, convex to bell-shaped becoming flat to uplifted, sometimes with a small umbo; white to cream or pale ochraceous gray, center sometimes darker to brownish. GILLS notched, close, 40-45 reaching stipe, broad, 3-5 subgills between neighboring gills; white to pale cream. STIPE 5-7 cm x 0.5-1.0 cm, equal down to club-shaped base; with small dark gray-brown scales (like scabers on Leccinum) on a whitish background. ODOR faint, but said to suggest bitter almonds, anise, fruit, cheese rind, or to become mealy-earthy. TASTE mild. HABITAT occasionally single but usually gregarious; short turf, grassy places, bare ground, in forests or in places where wood is stored and bark is discarded, on buried, rotting wood; late spring to fall. DISTRIBUTION at least WA, BC. SPORE DEPOSIT cream. MICROSTRUCTURES spores 7.5-8.8 x 4-5 um (Breitenbach), 8.5-10(11) x 4.5-5.5 um (Moser), 11 x 5 um (Bon), elliptic, slightly to finely verrucose, amyloid; pleurocystidia 55-60 x 6-8 um, "stinging hair" type (cylindric with hairy appearance in distal half); cheilocystidia not seen.Melanoleuca verrucipes
Melanoleuca verrucipes
Marc Donsky

 

REFERENCES

  1. Arora, David. 1986 Mushrooms Demystified Second Edition. Ten Speed Press, Berkeley.
  2. Bessette, Alan E., Bessette, Arleen R., Miller, Orson K. Miller, Hope H. 1995. Mushrooms of North America in Color: A Field Guide to Seldom-Illustrated Fungi. Syracuse University Press.
  3. Breitenbach, J., Kränzlin, F. 1991. Fungi of Switzerland Volume 3 Boletes and Agarics First Part. Edition Mykologia Lucerne.
  4. Gillman, Linnea Stewart, Orson K. Miller. 1977. “A study of the boreal, alpine, and arctic species of Melanoleuca.” Mycologia 69: 927-951.
  5. McKnight, Kent H., McKnight, Vera B. 1987. A Field Guide to Mushrooms North America. Peterson Field Guide Series. Houghton Mifflin, New York.
  6. Miller Jr., Orson K., Hope H. Miller. 2006. North American Mushrooms. A field guide to edible and inedible fungi. Falcon Guide.
  7. Smith, Alexander H. 1944. “New North American Agarics.” Mycologia 36: 242-262.
  8. Smith, Alexander H., Smith Helen V., Weber, Nancy S. 1979. How to Know the Gilled Mushrooms. Wm. C. Brown Company, Dubuque, Iowa.

 

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