Trial field key to the PLEUROTOID SPECIES in the Pacific Northwest

Prepared for the Pacific Northwest Key Council
By Dorothy E. Brown, Spokane Mushroom Club
Copyright © 1981, 2003 Pacific Northwest Key Council
Photo copyright held by each photographer
Do not copy photos without permission

Reformatted with revision by Ian Gibson Feb. 2003



 Note on Revision



 Key to Species





The following species have been added to the key: Ossicaulis lignatilis, Pleurotus pulmonarius, Pleurotus populinus, Panellus longinquus, Resupinatus striatulus, and Hohenbuehelia nigra. Hypsizygus tessellatus replaces Pleurotus elongatipes, and Pleurotus candidissimus is renamed Cheimonophyllum candidissimum. Pleurotus sapidus and Pleurotus ulmarius were deleted. The structure of the key was not altered except to accommodate these changes. I am grateful to Scott Redhead, and to Jim Ginns, Lorelei Norvell, and other members of Pacific Northwest Key Council, for help in clarifying species concepts. In 2008, Tectella patellaris was added.


All Pleurotoid mushrooms are gilled fungi and are lignicolous. Species vary in size from minute to large. Stems are generally eccentric (off-center) or lateral, plug-like or absent. Spores are roundish to elliptical and have smooth thin walls. Spores of Cheimonophyllum, Hohenbuehelia, Ossicaulis, Pleurocybella, Pleurotus, Panus, Phyllotopsis, and Resupinatus are non-amyloid; spores of Panellus are amyloid. Spore deposit is most often white but Phyllotopsis nidulans has light cinnamon reddish or pinkish spores, Panellus longinquus has dingy yellow-cream spores, Hypsizygus tessellatus has buff spores, Panellus serotinus has yellow spores and species in the Pleurotus ostreatus complex may have spores that are lilac-tinged. Crepidotus species, which are common and look somewhat similar, but are not considered Pleurotoid species, have brown spores and are not included.

Sometimes species may grow in solitary fashion, but it is more common to find many fruiting bodies to be observed at one time. Some species are gregarious, some clustered, and some shelving. Both conifer and hardwood areas provide habitat.

Regarding edibility, no poisonous species are known, but some are too minute, or too tough, or not desirable because of styptic, sour, or bitter flesh. (It must be noted that two members of Spokane Mushroom Club have reported nausea and stomach upset from eating Panellus serotinus.) Edible and choice species will be noted in individual descriptions.

In the following key, stem attachment is described as "eccentric" when stem is off-center; "lateral" is used when attachment to host is at edge of cap; "plug" describes a tough lateral attachment no longer than 2 cm.



Information and material has been gathered from many sources but special acknowledgement must be given to the publications of Dr. A. H. Smith and Dr. Orson Miller. Appreciation is expressed to Kit Scates for specimens, slides, assistance and advice.



1a Cap small (under 3 cm; often 0.6 cm or less)

1b Cap larger

2a Cap white

2b Cap colored

3a Stem absent; cap white, dry, covered with soft white hairs

................................................................................Cheimonophyllum candidissimum

(also known as Pleurotus candidissimus)

CAP 0.3-2.0 cm broad, shell-shaped inrolled at first -- expanding to nearly plane; white covered with soft white hairs; chalky appearance; soon becoming shriveled; flesh white, thin, pliant. GILLS reaching a point of attachment, subdecurrent, broad, fairly distant, narrowing toward ends; white with chalky appearance; edges finely fringed or torn. STEM insignificant or absent. HABIT and HABITAT decaying and dead wood of conifers and hardwoods; common in gregarious numbers; in scattered colonies fruiting in the fall. EDIBILITY apparently untested. SPORE PRINT white. MICROSTRUCTURES spores 5-6 x 4.5-5.5 um, round or nearly round, smooth, inamyloid.

3b Stem present or absent; if cap whitish then cap is viscid or bald or has partly slimy flesh

4a Stem present, gill edges prominently gelatinous, gelatinous layer in cap may be separable, growing on conifer wood

................................................................................Panellus mitis

(also known as Pleurotus mitis (Pers.: Fr.) Quelet)

CAP 0.5-0.8 cm long, 0.5-0.6 cm wide; spathulate to shell-like, flat to broadly convex; dull white or light gray -- becoming reddish clay color; covered with fine white canescence from appressed fibrils; the small fruitbodies contain a gelatinous upper layer and at gill edges; margin fringed; flesh is more or less spongy. ODOR not pronounced. TASTE mild. GILLS narrow, even, subdistant; white to pale pinkish cinnamon; edge gelatinous. STEM laterally attached; 0.1-0.2 cm long, 0.1 cm or less wide; flattened and dilated above; covered with minute white fibrils over a pallid ground color; somewhat mealy. HABIT and HABITAT scattered or in clusters on sides of conifer logs and sticks -- particularly abundant on Western Larch; fruits in September and October. EDIBILITY unknown. SPORE PRINT white. MICROSTRUCTURES spores, 3.5-6.0 x 0.9-1.2 (1.5) um, sausage-shaped, somewhat curved, almost cylindric, smooth, thin-walled, amyloid. REMARKS "mitis" means "a thread" in Greek; molecular research indicates that a new genus may be needed for this species.

4b Stem present or absent; gill edges not prominently gelatinous; cap may be viscid but without a separable gelatinous layer, growing on Red Alder

................................................................................Panellus longinquus (See also 9a.)

(also known as Pleurotopsis longinqua (Berk.) E. Horak.)

CAP 0.2-4 cm wide and 0.1-2.0 cm long, rounded when young, at maturity fanshaped, kidney-shaped or irregularly lobed, convex in profile but often depressed near attachment, margin inrolled; hygrophanous, pale ivory, faint peach, or tan, in age becoming pinkish on a camel brown background, and finally in some specimens brown with purple-brown discoloration, when dried becoming translucent waxy yellow or opaque golden brown or purple-brown; translucent when wet and often viscid, opaque and concentrically wrinkled when dry; flesh firm, fibrous; white to pale pinkish tan. GILLS short decurrent onto stem or pseudostem, close when young, subdistant with age; ivory, pale yellow-cream, or peach like young cap, sometimes drying with grayish tint; sometimes transverse wrinkles present. STEM absent, or when present lateral, always fairly broad at gill attachment, 0.1-0.9 x 0.1-0.5 cm, ivory, yellow-cream, peach or brown, often frosted on inferior surface, usually with some white coarse tomentum toward the base and a small mat of hyphae extending onto substrate. ODOR and TASTE not distinctive. HABITAT on branches and logs of Red Alder, rarely stumps of Western Hemlock. SPORE PRINT dingy yellow-cream. MICROSTRUCTURES spores 6-11.5(13.5) x 3-5.0(6) um, elliptic, oblong or cylindric, occasionally slightly dumbbell shaped, kidney-shaped or curved sausage-shaped, smooth, amyloid. REMARKS spore deposit dingy yellow-cream. Panellus mitis is generally less than 2 cm wide, grows on conifers, and has narrower spores and prominently gelatinized gill edges; Panellus stipticus has peppery to bitter taste, and smaller spores, among other differences.Panellus longinquus
Panellus longinquus
George Barron

5a (2b) Cap usually less than 1 cm broad, chocolate brown to black; if buff then usually less than 0.5 cm broad

................................................................................Resupinatus applicatus

CAP 0.7-1.5 (2.0) cm; fanshaped to shell-shaped; chocolate brown to black when wet, not striate or translucent striate, ash-gray and non-striate when dry; basal 1/3 to 2/3 covered with shaggy stiff coarse tomentum, especially dense over pseudostem, margin bald to pruinose; flesh gelatinous and black in mass. GILLS decurrent and radiating from pseudostem, moderately narrow and close; dark brown when revived, edges whitish; edges entire. STEM lateral pseudostem, 0.2-0.5 cm broad. HABITAT occurs most commonly on bark of hardwood logs such as oak and maple, or on hard rinds formed on hardwood logs by fungi such as Ustulina deusta. MICROSTRUCTURES spores (4.0)4.4-6.0 x 4.0-4.8 um, round or nearly round, smooth, inamyloid. REMARKS Many of the descriptions of Resupinatus applicatus confuse it with Resupinatus striatulus which occurs at least in BC, but is very small (0.15-0.7 cm but averages 5-10 times smaller than R. applicatus). It is cupshaped rather than fanshaped, dorsally or laterally attached; beige, pinkish brown, gray-brown, to blackish, darkening on drying, sometimes has striate or sulcate margin, has gills that are cap-colored or paler and radiate from the point of attachment, and grows on undersides of old and well-rotted conifer or deciduous wood that is without bark and is usually soft and white-rotted. Spores are (3.3)4.0-6.0 x (3.1)3.5-5.0 um, round or nearly round, inamyloid, and colorless. Resupinatus species have a distinctive cell surface structure. This account of the Resupinatus species is derived from Thorn whose specimens of Resupinatus applicatus were eastern in North America. Some authors regard the two as synonyms. Another species that will key out here and has been recorded from Oregon, Montana, and Yukon Territory is Hohenbuehelia nigra (Schw.) Singer (previous names including Pleurotus niger (Schw.) Sacc.; Resupinatus niger (Schw.) Murrill). Features are the following: CAP up to 0.8 cm broad and 0.6 cm deep, cup-shaped to shell-shaped, dorsally attached; black, with olive brown margin (as revived); bald except for a few scattered white hairs, not striate. GILLS radiating from point of attachment, moderately narrow and close; dingy olive brown (as revived); markedly spiny under 10x. STEM sessile or with short pseudostem. HABITAT found on dead deciduous wood of Juglans (walnut) and Alnus (alder). SPORE PRINT white. MICROSTRUCTURES spores (6.0)7.5-10(10.5) x 3.5-4.5 um, smooth, elliptic-beanshaped, inamyloid; lanceolate metuloid cheilocystidia 33-75 x 8-12(14) um, as well as smaller fusoid-clavate cystidia with drawn-out neck.

5b Cap usually more than 1 cm broad, ochraceous to buff or dull brown or purplish

6a Cap purple to purple drab with lilac tinges

................................................................................Panellus ringens

(also known as Panus ringens)

CAP (0.5) 1.0-3.0 cm in diameter; puckered fan shape; light purple to purple drab or lilac with vinaceous tints, fading in age; dried material vinaceous gray to lilac gray at point of attachment; sometimes irregularly striate, margin even to somewhat crenate (scalloped); with pallid pubescence dense over lateral attachment of cap; flesh thin. GILLS radiating from point of attachment, fairly well spaced; fawn to pink, fading in age to reddish brown when dried. STEM absent. HABIT and HABITAT birch sticks and limbs on ground; usually several to gregarious; sometimes nearly imbricate; fruiting in late summer and fall; sometimes collected in winter. DISTRIBUTION O.K. Miller examined material from ID, and D. Lowe reported it from BC, but records are sparse. EDIBILITY unknown. SPORE PRINT white. MICROSTRUCTURES spores (4.0) 5.0-7.0 x 1.2-2.0 um, oblong to sausage-shaped, amyloid. REMARKS "ringens" means "wide open", from Latin.

6b Cap ochraceous to light buff or dull brown

7a Partial veil not present, taste unpleasant, stem short

................................................................................Panellus stipticus

CAP (0.5) 1.2-3.2 cm long, 1.2-1.5 (2.5) cm wide, plane to convex with crenulate (finely scalloped) margins in age, fan-shaped; pale to light ochre-buff to tannish brown; dry with wooly hairs; areolate; several concentric ribs or zones; flesh thin, tough, firm, pinkish tan. ODOR not distinctive. TASTE astringent unpleasant, bitter sour, Arora says usually acrid or astringent. GILLS narrow, close, often forked; ochraceous buff, ochraceous salmon or pale cinnamon, may be tawny olive in age; luminescent. STEM usually eccentric, often lateral, somewhat constricted just at base, 0.6-1.2 cm long, up to 0.8 cm wide; dull white; minutely fibrillose; veil absent. HABIT and HABITAT logs, limbs, stumps of hardwood, also on wood in service (such as fences and structural timbers); grows usually in lightly packed imbricate (shelving) clusters as a saprophyte; fruits in September, October and November, common. EDIBILITY non-poisonous but non-edible because of bitter, sour, and astringent flesh. SPORE PRINT white. MICROSTRUCTURES spores 3.5-4.6 x 1.2-2.2 um, elliptical to somewhat sausage-shaped, amyloid. REMARKS "stipticus" refers to styptic or astringent qualities, from Latin.Panellus stipticus
Panellus stipticus
Kit Scates Barnhart

7b Partial veil covers gills when young, leaving hanging remnants on margin, taste mild, stem usually absent

................................................................................Tectella patellaris

CAP 0.7-2.0cm across, circular, with concave to flattened gill-bearing surface facing downward, attached at its edge or upper surface, margin inrolled; ocher to dingy brown; slimy to viscid when young, becoming dry and fibrous to floccose-scaly, margin decorated with hanging pieces of veil tissue; flesh tough, ocher. ODOR and TASTE not distinctive. GILLS close to distant, narrow; pale brownish; pale buff partial veil covering gills when young. STEM usually absent, if present then very small. HABIT and HABITAT in groups or clusters on logs and fallen branches of hardwoods, various times of year, uncommon. EDIBILITY unknown. SPORE PRINT white. MICROSTRUCTURES spores 3-5 x 1-1.5 microns, cylindric or curved cylindric, smooth, weakly amyloid. REMARKS The partial veil in a stemless agaric is very unusual. Tectella operculata (Berk. & M.A. Curtis) Earle is considered to be the correct name by some authors.

8a (1b) Cap having veil when young; cap white, grayish or ochraceous

................................................................................Pleurotus dryinus

(also known as Pleurotus corticatus)

CAP 4-10 cm; roundish but irregular, often humped; whitish, grayish, ochraceous - sometimes yellowish in age; partial veil when young; involute (inrolled) margin with velar remains; covered with felt that backs up into soft grayish scales; flesh white and thick but soon tough and hard. ODOR and TASTE mild and agreeable. GILLS decurrent, anastomosing, broad, close; white and then yellow; decurrent edges uneven. STEM eccentric, usually horizontal; whitish but becoming yellow when bruised, or with age; firm, hard, fibrous, cylindric; sometimes with ringlike velar remains; cortina whitish; finely woolly, disappearing early. HABITAT usually deciduous trees - rarely on conifers; fairly frequent on trunks of trees from September to November. EDIBILITY Caps may be used but are mild and agreeable only when young and tender. According to Kauffman there is a taste of bitter almonds. SPORE PRINT white. MICROSTRUCTURES spores, 9-12(17) x 3.5-5 um. REMARKS "dryinus" means "dry", from Latin.Pleurotus dryinus
Pleurotus dryinus
Michael Beug

8b Cap lacking veil when young; colors various

9a Cap like a rolled upright leaf, shoehorn-like, cap brown - feels lubricous (soapy)

................................................................................Hohenbuehelia petaloides (See also 19a.)

(also known as Pleurotus petaloides and Hohenbuehelia petalodes)

CAP 2-5 cm broad near outer margin and 5-9 cm long (but usually smaller); like a rolled upright leaf - shoehorn-like; spathulate, fan-shaped, or funnel-shaped with one side open - tapering to a stemlike base; pale brown to grayish brown; surface moist or gelatinous but not viscid; usually more or less canescent (hoary); margin always somewhat inrolled and often faintly striate in age - also variously lobed or wavy; flesh white, watery avellaneous, thickish, pliant, cartilaginous. ODOR and TASTE mild. GILLS decurrent down to the stem-like base, narrow and very crowded; pale grayish buff or whitish becoming creamy; edges crenulate (finely scalloped); pruinose under a lens. STEM lateral, short, strophic (turning), white, hairy. HABIT and HABITAT decaying wood of hardwoods and conifers (favors stumps of hemlock in northern regions); scattered to gregarious; sometimes appears terrestrial when fruiting from underground wood; has been found in cultivated places; fruits in summer and fall. EDIBILITY not choice. SPORE PRINT white. MICROSTRUCTURES spores 7-9 x 4.5-5 um. REMARKS not common. "petaloides" means petal-like.Hohenbuehelia petaloides
Hohenbuehelia petaloides
Kit Scates Barnhart

9b Cap otherwise

10a Fanshaped, kidney-shaped or irregularly lobed cap up to 4 cm wide, hygrophanous pallid to pale orange to pinkish brown, stem absent or lateral, growth on Red Alder, yellow-cream spore deposit, (cylindric spores)

................................................................................Panellus longinquus (See 4b.)

10b Not with the above combination of characters

11a Caps shelving; little or no stem, stem if present lateral or eccentric

11b Caps not shelving; stem short to long, lateral, eccentric or sometimes central

12a Cap with long stiff hairs

................................................................................Panus rudis

(See also 16b.)

CAP 1.5-7 cm broad; convex, fan-shaped; margin inrolled, often irregularly lobed; dry; long stiff hairs; flesh white, thin, tough. TASTE slightly bitter. GILLS extending down stem; narrow, close; white to pallid; smooth edges. STEM lateral, short, stout, hairy; colored like cap. HABIT and HABITAT hardwood logs and stumps; sometimes single but usually several together; numerous in spring, summer and fall. EDIBILITY taste slightly bitter but non-poisonous. SPORE PRINT white. MICROSTRUCTURES spores 4.5-7 x 2-5.3 um, smooth, short, elliptical, inamyloid. REMARKS [By 2011 usually known as Lentinus strigosus.] "rudis" means "raw, coarse, rough", from Latin.Lentinus strigosus
Lentinus strigosus
Steve Trudell

12b Cap more or less smooth (may be downy-floury)

13a Cap tan tinted lilac, to reddish brown; usually in small clusters on dead hardwood stumps and logs

................................................................................Panus conchatus

(also known as Panus torulosus (Pers. ex Fr.) Fr.)

CAP 1.5-8 cm broad; broadly convex; somewhat depressed in center in age; margin inrolled; tan tinted with lilac, to reddish brown, variable; dry; minutely downy at first, but soon smooth without hairs; flesh white, thick, firm, leathery. ODOR aromatic. TASTE somewhat like turnip. GILLS extending down stem, narrow and fairly well separated; violet at first fading to tan; edges even. STEM off-center, 2-6 cm long, 2-3 cm thick; tough, tan covered with fine violet-tinted hairs; veil absent. HABIT and HABITAT on stumps and logs of hardwoods; several together in numerous clusters in spring, summer, and fall. EDIBILITY rated inedible because it is so tough, but McIlvaine reported it much esteemed in France! SPORE PRINT white. MICROSTRUCTURES spores, 5-7.5 x 2.5-3 um, elliptical, thin-walled, inamyloid. REMARKS "conchatus" means "shell-like" (Latin); "torulosus" means "a tuft of hair" (Latin).

13b Cap whitish, may become somewhat grayish or gray-brownish or yellow-brownish, at most with faint rose to pale vinaceous tints on disc, growing on Populus and other hardwoods, often on living trees

14a Cap becoming marbled with watery spots, (spores 4-5(6) x 4-4.5 um, round to nearly round)

................................................................................Hypsizygus tessellatus

(Hypsizygus elongatipes (Peck) Bigelow and Hypsizygus marmoreus (Peck) Bigelow are synonyms; Hypsizygus ulmarius (Bull.: Fr.) Redhead is not a synonym.)

CAP 2-14 cm broad, convex, nearly flat at maturity; pinkish cream with distinctive darker, round water spots over the center; moist, smooth without hairs; flesh firm but not tough, white to pinkish buff. GILLS adnexed (notched), with a thin line on the upper stem, subdistant, broad, veined, buff to pinkish buff. STEM 4-22 x 0.4-2.0 cm, equal or gradually tapering toward base, often curved or bent, white, smooth except near to top where there is white down, and the base, which has white stiff hairs; veil absent. HABIT usually several stalks from a common base. HABITAT on poplar or occasionally other hardwoods. EDIBILITY edible. SPORE PRINT buff. MICROSTRUCTURES spores 4-5(6) x 4-4.5 um, round to nearly round, smooth. REMARKS The description above is derived from Miller's description of Pleurotus elongatipes, except the habitat and microstructures which are from Redhead. Much confusion has surrounded this species. Arora, Lincoff, Bessette, and Barron all give Pleurotus ulmarius as a synonym of this species. Scott Redhead says that Hypsizygus tessellatus (Bull. ex Fr.) Singer is a species that often grows caespitosely, in North America on poplar and Sugar Maple, occasionally on Betula, Ulmus, Abies, and Fagus, has a guttate-marmorate cap when fresh, (Bulliard's 'tessellatus' emphasizes the spots, Peck's 'marmoreus' the lines between, but cap not cracked in a tessellated manner), and has small round to nearly round spores 4-5(6) x 4-5 um, but H. ulmarius (Bull.:Fr.) Redhead in contrast usually grows solitarily, in North America frequently on elm and box elder (Acer negundo), occasionally on Populus and other Acer species, has a smooth not guttate cap when fresh which often becomes areolate-cracked with age and has larger nearly round to broadly elliptic spores (5)5.5-6(7) x 5-5.5(6) um; both species are found in Eurasia, the latter is found in North America in areas east of the continental divide and generally central latitudes, H. tessellatus (Bull. ex Fr.) Singer is found is found from coast to coast and north to the Yukon.

14b Cap not becoming marbled with watery spots, (spores 4-6 x 3.0-3.5 um, elliptic to broadly elliptic)

................................................................................Ossicaulis lignatilis

(previously known as Pleurotus lignatilis)

CAP 5-12 cm or even larger, convex to cushion-shaped, becoming flat to shallowly depressed, with inrolled to incurved edges, often becoming indented or incised, often chalky-white, with or without faint rose to pale vinaceous tints on disc, may be grayish initially, or become somewhat grayish or gray-brownish or yellow-brownish; dry, opaque, may be downy-floury; flesh tough, fleshy, with conspicuous membranous layers. ODOR fungal, sometimes fleetingly farinaceous when first cut. TASTE not distinctive to strongly fungal. GILLS adnate to adnexed or decurrent by short tooth, crowded to subcrowded, moderately narrow (up to 0.6 cm broad); white but drying yellowish white, when old sometimes yellowing, browning; with even or eroded edges. STEM 1-6 x 0.15-1 cm, sometimes longer or thicker, often short and strongly curved, usually swollen in lower part, usually off-center, sometimes more or less central, often with immature fruiting bodies close by; colored like cap, occasionally with faint vinaceous-rose tint; with a surface similar to cap, often slightly more matted-roughened at top, otherwise like suede, white mycelial strands often noted near base. HABITAT on living or dead hardwood or sometimes conifer trunks. EDIBILITY reported in Europe to be edible. SPORE PRINT white. MICROSTRUCTURES spores 4-6 x 3.0-3.5 um, elliptic to broadly elliptic, smooth, inamyloid; coralloid hyphae in the cap cuticle, mucilaginous coating on hyphae of stem.

15a (11a) Cap quite densely hairy

15b Cap minutely hairy or glabrous (bald)

16a Cap orange to orange buff; bad odor

................................................................................Phyllotopsis nidulans

(also known as Pleurotus nidulans (Pers.: Fr.) Kummer)

CAP 3-8 cm broad; sessile; fan-shaped; broadly convex; bright orange to orange buff, ochre yellow; margin inrolled at first; dense hairs over dry surface; flesh duplex with upper layer orange buff and lower layer very pale orange buff, thick. ODOR disagreeable with "sulphur component as in old cabbage" according to A.H. Smith; like sewer gas or rotten eggs according to Arora. GILLS adnate, narrow, close; bright orange to yellow or orange buff. STEM absent; veil absent. HABIT and HABITAT on hardwood and conifer logs and stumps; in shelving groups early summer through fall. EDIBILITY non-poisonous but not desirable. SPORE PRINT light cinnamon reddish, pinkish or pinkish brown. MICROSTRUCTURES spores 5-8 x 2-4 um, elliptical to sausage-shaped, smooth, inamyloid. REMARKS "nidulans" refers to a nest.Phyllotopsis nidulans
Phyllotopsis nidulans
Michael Beug

16b Cap pinkish tan to light reddish brown; no odor

................................................................................Panus rudis (See 12a.)

17a (15b) Cap greenish, purplish, slate gray or orangish; gills often orange or orange-tinted

................................................................................Panellus serotinus

(also known as Sarcomyxa serotina (Schrad.: Fr.) Karst.)

CAP 2.5-6 (10) cm broad, 2-3.5 cm wide; shell-like, fan-shaped, rolled toward the gills, margin sometimes rolled and wavy; dark ivy greenish, olive ochre to deep buff, occasionally toned purple over the margin; cuticle thick and glutinous; flesh white, thick, mucilaginous, duplex with upper gelatinous layer. ODOR and TASTE mild. GILLS adnate, narrow, close to subdistant; pale orange to honey yellow, sometimes yellowish olive to brownish olive, rarely cinnamon buff at margin. STEM absent - attachment is a basal plug covered with dense white woolly hairs. HABIT and HABITAT on various hardwoods and conifers; sides of logs and sticks; occasionally solitary but usually imbricate (shingled); common in late September and October, and often fruiting later in the fall season. EDIBILITY not choice, sometimes bitter. Two members of Spokane Mushroom Club reported nausea and stomach upset from ingestion. SPORE PRINT yellow. MICROSTRUCTURES spores 4.4-5.5 x 1.0-1.5 um, sausage-shaped to cylindric, smooth, amyloid. REMARKS "serotinus" means late, referring to late fruiting in the fall season.Panellus serotinus
Panellus serotinus
Kit Scates Barnhart

17b Cap not colored as above

18a Cap pristine white and transparent looking; flesh extremely thin

................................................................................Pleurocybella porrigens

(also known as Nothopanus porrigens (Pers.) Singer, Pleurotus porrigens (Pers. ex Fr.) Kuehner & Romagnesi, Pleurotellus porrigens (Pers. ex Fr.) Kummer, and Phyllotus porrigens (Pers. ex Fr.) P. Karst.)

CAP 2-10 cm broad, 4-8 cm long; convex when young, petal-like to fan-shaped; pristine white, milk-white that may yellow slightly in old age; margin inrolled at first, spreads only in age and then often gets lobed and wavy; shiny, minutely hairy, dry; white flesh thin and pliant. ODOR and TASTE not pronounced. GILLS extending to base of stem, narrow and crowded; white to cream. STEM absent or just a plug-like attachment to the host; veil absent. HABIT and HABITAT on sides of conifer logs and stumps; often hemlock, Douglas-fir, Silver Fir; fruits in overlapping clusters in late summer and fall. EDIBILITY rated as a good edible. SPORE PRINT white. MICROSTRUCTURES spores 6-7 x 5-6.5 um, subglobose to globose, smooth, inamyloid. REMARKS "porrigens" means "spread out" (Latin).Pleurocybella porrigens
Pleurocybella porrigens
Michael Beug

18b Cap tannish, brownish

19a Cap brown, wedge-shaped (shoehorn-shaped), feels lubricous (soapy)

................................................................................Hohenbuehelia petaloides (See 9a.)

19b Cap ash-gray, tannish, (if brown, not as above), no gelatinous layer or touch

(Pleurotus ostreatus complex)

This complex is difficult to separate except by mating studies: while the following characters may lead to one member's being more probable than another, collections will usually be best identified as Pleurotus ostreatus complex. Vilgalys et al. (1993) established the presence of Pleurotus populinus and P. pulmonarius in the Pacific Northwest. Pleurotus ostreatus is recorded from the Pacific Northwest prior to the 1993 differentiation including collections from alder described as up to 20 cm across, with lilac spores, (Bandoni & Szczawinski 1964).

20a Cap ivory white to pinkish gray or tannish, seldom over 9 cm wide, gills subdistant, spore print buff, spores (8) 9-12 (15) x 3-5 um, usually growing on Black Cottonwood (Populus trichocarpa) or aspen (Populus tremelloides and Populus tridentata), recorded May to July, but also October

................................................................................Pleurotus populinus

CAP 4-6 (9) cm wide, convex, oyster-shell-shaped to fan-shaped, the margin inrolled at first; pinkish gray to ivory white; dry, smooth, downy over the lateral point of attachment. GILLS decurrent over the short point of attachment, subdistant, 2 tiers of subgills, broad (0.5-1.0 cm), nearly white to cream. STEM 1.0-1.5 x 0.6-1.0 cm, lateral, equal or tapering to a narrow base, gills extending almost to the downy base. ODOR not distinctive to anise-like. TASTE mild and pleasant. EDIBILITY delicious (Arora for P. ostreatus complex). HABITAT single to numerous and often shingled on limbs, stumps, or logs of hardwood trees, especially Black Cottonwood (Populus trichocarpa) and aspen (Populus tremelloides and Populus tridentata), collections were mostly in May to July but also in October. SPORE PRINT buff-colored. MICROSTRUCTURES spores (8) 9-12 (15) x 3-5 um, narrowly elliptic, smooth, inamyloid; cheilocystidia 19-38 x 4-7 um, fusiform, ventricose-rostrate, capitulate, tibiiform to lecythiform, sometimes with an elongate hyphal extension at the apex, pleurocystidia 31-33 x 4.6-7.5 um, rare to numerous, capitulate; clamps present in all tissues. REMARKS Pleurocybella porrigens somewhat similar but smaller, thinner, and fades from white; Panellus serotinus has a yellow stem punctate with brownish scales, gills with ocher yellow colors, and cap commonly with greenish or violet tones.Pleurotus populinus
Pleurotus populinus
Steve Trudell

20b Cap off-white, tan, brown, deep gray, bluish olive to olive-black, may be over 9 cm wide; gills close to crowded, spore print white, yellowish, buff, lilac, lilac-gray, or light purplish vinaceous, spores 7.5-10 (11) x 2.8-4 (4.5) um, growing on hardwoods (including Populus) or conifers, at various seasons

21a Cap tan, brown, gray-brown, olive-black, often over 9 cm wide, young caps semicircular; recorded at all times of year but peak fruiting in winter, growing usually on hardwoods; spore print lilac to lilac gray to light purplish vinaceous

................................................................................Pleurotus ostreatus

(Pleurotus columbinus Quél. is no longer considered an independent species, but is said to have a bluish brown to greenish gray color.)

CAP (4) 6-15 (25) cm wide, convex, spathulate, scallop-shaped to mussel-shaped, margin inrolled; whitish, yellow to grayish yellow, light tan to dark brown, also drab to cinnamon drab or pale cinnamon-pink; moist when young but never viscid, soon dry; finely downy over the lateral point of attachment to stem, smooth over the rest of the surface; flesh to 1 cm or 2 cm thick, firm, somewhat fibrous, white. GILLS adnate to mostly decurrent, close to crowded, broad (0.5-1.5 cm), with two tiers of subgills, sometimes forming a network near the point of attachment; dull whitish to pale pinkish buff; edge smooth at first, becoming eroded in age. STEM (0.5) 1-3 x 0.3-2.0 (3.0) cm, laterally attached, stocky, nearly equal; dry, white pubescent to strigose at base. ODOR pleasant and anise-like, becoming fungoid and unpleasant in age. TASTE mild and pleasant in fresh specimens. HABIT and HABITAT single, or more usually in large shingled clusters on the sides of stumps, logs and branches of hardwood trees, or less often on conifers (pine and true fir), fruiting during cool weather wherever hardwood hosts are found, especially fond of riparian habitat. SPORE PRINT lilac to lilac-gray, to light purplish vinaceous. MICROSTRUCTURES 7.5-9.5 x 3.2-4 um, narrowly elliptic, smooth, inamyloid, cheilocystidia and pleurocystidia infrequent to numerous, most often on gill edge, 14-30 x 3.5-8 um, clavate-capitate, colorless, thin-walled; clamp connections present in all tissues. REMARKS Vilgalis et al.(1993) from whom the descriptions of the P. ostreatus complex are derived, state, "It is difficult if not impossible to distinguish North American field collections of P. pulmonarius from P. ostreatus. However, differences in their mating behaviour, distribution, and seasonality indicate that they are distinct species".Pleurotus ostreatus group
Pleurotus ostreatus group
Michael Beug

21b Cap white, tan, gray-brown, seldom over 9 cm wide, young caps lung-shaped; fruiting mainly on conifers in western US (May to August and also February) but on hardwoods in eastern US (July to November, and also April), recorded in BC on Acer macrophyllum (Bigleaf Maple); spore print white, yellow, buff to lavender gray when heavy

................................................................................Pleurotus pulmonarius

CAP 2.5-9 cm, spathulate, oval to conch-shaped, nearly flat when old; white to grayish white, pinkish brown or light orange brown often with a hint of gray, light brown or brown; dry, bald, often with shallow surface indentations near the margin and point of attachment; flesh firm, sometimes water-soaked near the cap skin, dull white. GILLS short decurrent to decurrent, close to crowded, with 2 tiers of subgills, moderately broad (0.5-1.0 cm), often anastomosing and intervenose along stem; white to slightly cream color in age. STEM 1-2 cm long, lateral to subcentral (nearly central); white; covered with irregular shallow ridges that are sometimes intervenose to almost poroid and reticulate, extending from the gills, densely bristly to downy over the base at the point of attachment. ODOR pleasant, with a vague anise-like aroma when fresh. TASTE mild at first and pleasant, becoming strongly fungal. HABIT and HABITAT in shingled clusters, rarely single, on logs, limbs and stumps of conifers or hardwoods. SPORE PRINT variable, white, yellowish, buff to lavender gray when heavy. MICROSCOPIC spores 7.5-10 (11) x 2.8-4 (4.5) um, narrowly elliptic, smooth, inamyloid; cheilocystidia 26-37 x (4) 5-7.5 um, capitate to fusiform, colorless, thin-walled, often with a basal clamp connection, pleurocystidia similar to cheilocystidia, from numerous to very scarce.Pleurotus pulmonarius
Pleurotus pulmonarius
Steve Trudell



anastomosing - joining together, forming a network

areolate - surface cracked into plaques or blocks, like the cracking that occurs when mud dries in the sun

astringent - causing a contraction or pucker of the mouth membranes

avellaneous - dull grayish brown, hazel-brown, or light gray yellow brown, or closer to drab, or gray tinged with pink, in Ridgway 1912 closer to pinkish buff

capitate - with a head or cap, abruptly enlarged at top

capitulate - with a small head

cartilaginous - of tissue, tough, not fibrous

complex - a cluster of taxonomically related similar species typified by a particular species, as in Pleurotus ostreatus complex

cortina - a web-like or silky veil extending from the cap margin to the stem in young mushrooms of certain species, soon disappearing or leaving remnants on stem or cap margin

cuticle - the skin or surface layer of cells; same as pellis

disc - center of the cap

drab - a dull medium or brownish gray, dark gray with shades of yellow; gray with violet overtones; in Ridgway 1912, a gray-brown

duplex - flesh of two distinct textures

eccentric - off center; of stem attachment, attached away from center of cap but not at its edge

entire - with even edges: of gills, not serrated or toothed

equal - of a stem, the same diameter throughout its length

even - of cap margin, means not wavy or lobed; of gill edges, means not toothed, eroded, fringed etc.

farinaceous - of odor, with the smell of fresh ground meal from whole grain, especially wheat

fibrillose - composed of delicate fibers which are long and evenly arranged on the surface

fusiform - spindle-shaped, fairly slender and narrowing from middle to both ends

gelatinized - appearing or having become gelatinous

gelatinous - jelly-like in consistency or appearance

glabrous - bald

globose - spherical

guttate - having drop-like spots; drop-shaped

hygrophanous - cap surface changing color markedly as it dries, usually having a water-soaked appearance when wet and turning a lighter opaque color on drying

imbricate - each growing just above the others, as with roof shingles

lanceolate - like a lance, many times longer than broad, and tapering; of cystidia somewhat wider in middle and tapered at both ends

lateral - of a stem, attached to the side of the cap

lecythiform - of cystidia, wide at base with middle tapered into narrow neck and top swollen into a head, like a bowling pin

lignicolous - living in, on, or out of wood

lubricous - greasy or slippery or oily but not viscid (sticky) or slimy

membranous - like a membrane or skinlike or somewhat like kleenex

metuloid - encrusted cystidium thick-walled at maturity and rounded at the top, or at least not pointed

pleurotoid - resembling in general form the genus Pleurotus, may be applied to any gilled mushroom either without a stem or with a stem attached in a lateral or off-center manner

pliant - being pliable without breaking, flexible, not rigid or firm

poroid - with pores that are the openings of united tubes

pruinose - looking finely powdered or finely granular

pubescence - a covering of soft short downy hairs

pubescent - covered with soft short downy hairs

punctate - marked with dots consisting of hollows, depressions, spots, raised-joined scales, or agglutinated fibrils, all very small

reticulate - covered with a network of interlacing lines, ridges, or folds

riparian - relating to or situated along the banks of a river or stream

sessile - lacking a stem

spathulate - shaped like a spatula or spoon, oblong with a narrowing base

strigose - having long stiff hairs

styptic - causing contraction of tissues

subcrowded - a term used occasionally of gill spacing, intermediate between close and crowded, might also be used to mean more or less crowded

subdecurrent - of gills, meaning short decurrent or nearly decurrent or somewhat decurrent (i.e. intermediate between adnate and decurrent, when attachment extends slightly further down stem than when adnate)

subgills - the short gills that do not span the entire distance from margin to stem

substrate - the material that a fungus is growing on

sulcate - grooved, furrowed

tessellated - like a mosaic, with pieces fitted together, sometimes used to mean mottled

tibiiform - of cystidia, somewhat ventricose (wider in middle) with long narrow neck and apex swollen into a head, supposedly like the tibia bone

tomentum - a covering of densely matted woolly hairs

velar - of the veil




(References were not included in the original key. The following are relevant to the minor revision.)

  1. Bandoni, Robert J., and Adam F. Szczawinski. 1964. Guide to Common Mushrooms of British Columbia. British Columbia Provincial Museum Handbook 24. 179 pp.
  2. Jin, J-K, Hughes, K.W. and Petersen, R.H. 2001. "Phylogenetic relationships of Panellus (Agaricales) and related species based on morphology and ribosomal large subunit sequences." Mycotaxon 79:7-21.
  3. Libonati-Barnes, S.D., S.A. Redhead. 1984. "Panellus longinquus ssp. pacificus. A new west coast North American agaric associated with red alder." Mycotaxon 20(1): 205-212.
  4. Miller, Orson K. 1973. Mushrooms of North America. 360 pp.
  5. Redhead, S.A. 1984. "Mycological observations 13-14: on Hypsizygus and Tricholoma." Trans. Mycol. Soc. Japan 25: 1-9.
  6. Redhead, S.A., James H. Ginns. 1985. "A reappraisal of agaric genera associated with brown rots of wood." Trans. Mycol. Soc. Japan 26: 349-389.
  7. Redhead, S.A. 1986. "Mycological Observations 15-16: On Omphalia and Pleurotus." Mycologia 78(4): 522-528.
  8. Thorn, R.G., G.L. Barron 1986. "Nematoctonus and the Tribe Resupinateae in Ontario, Canada." Mycologia 25(2): 321-453.
  9. Thorn, R. Greg, Jean-Marc Moncalvo, C.A. Reddy, Rytas Vilgalys. 2000. "Phylogenetic analysis and the distribution of nematophagy support a monophyletic Pleurotaceae with the polyphyletic pleurotoid-lentinoid fungi." Mycologia 92:(2) 241-252.
  10. Vilgalys, Rytas, Ajiri Smith, Bao-Lin Sun, Orson K. Miller Jr. 1993. "Intersterility groups in the Pleurotus ostreatus complex from the continental United States and adjacent Canada." Can. J. Bot. 71(1): 113-128.
  11. Watling, R., Norma M. Gregory. 1990. British Fungus Flora Agarics and Boleti 6 Crepidotaceae, Pleurotaceae and other pleurotoid agarics. Royal Botanic Garden, Edinburgh.




    C. candidissimum (Berk. & M.A. Curtis) Singer 3a
    H. nigra (Schw.) Singer 5a
    H. petaloides (Bull. ex Fr.) Schulz. 9a, 19a
    H. tessellatus (Bull. ex Fr.) Singer 14a
    L. strigosus Fr. 12a, 15b
       = Panus rudis Fr  
 OSSICAULIS Redhead & Ginns  
    O. lignatilis (Pers.: Fr.) Redhead & Ginns 14b
 PANELLUS P. Karst.  
    Panellus longinquus (Berk.) Singer 4b, 10a
       = Pleurotopsis longinqua (Berk.) Horak  
    P. mitis (Pers. ex Fr.) Singer 4a
    P. ringens (Fr.) Romagn. 6a
    P. stipticus (Bull. ex Fr.) Karsten 7a
    P. serotinus (Pers. ex Fr.) Kuehner 17a
       = Sarcomyxa serotina (Schrad.: Fr.) Karst.  
 PANUS Fr.  
    P. conchatus (Bull. ex Fr.) Fr. 13a
       = Panus torulosus (Pers. ex Fr.) Fr.  
    P. rudis Fr. 12a, 15b
 PHYLLOTOPSIS E.-J. Gilbert & Donk ex Singer  
    P. nidulans (Pers. ex Fr.) Singer 16a
    P. porrigens (Pers. ex Fr.) Singer 18a
       = Nothopanus porrigens (Pers.) Singer  
       = Pleurotus porrigens (Pers. ex Fr.) Kuehner & Romagnesi  
       = Pleurotellus porrigens (Pers. ex Fr.) Kummer  
       = Phyllotus porrigens (Pers. ex Fr.) P. Karst.  
       = Panellus longinquus (Berk.) Singer  
 PLEUROTUS (Fr.) P. Kumm.  
    P. dryinus (Pers. ex Fr.) P. Kumm. 8a
    P. ostreatus (Fr.) P. Kumm. 21a
    P. populinus O. Hilber & O.K. Miller 20a
    P. pulmonarius (Fr.) Quél. 21b
 RESUPINATUS (Nees) Gray  
    R. applicatus (Bat. ex Fr.) S.F. Gray 5a
    R. striatulus (Pers.: Fr.) Murrill 5a
    T. patellaris (Fr.) Murrill 7b


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