Practical ecological knowledge for the temperate reader.

Pleurotus Sp. - Oyster Mushrooms

Family: Pleurotaceae [E-flora]

Local Species


Pleurotus dryinus - Veiled oyster mushroom

Summary: "Features include whitish or grayish, dry cap with soft fibrils or scales; a fleeting veil on the margin and stem when young; decurrent, close, whitish gills that form grooves on stem; off-center, whitish, dry stem; and growth on living hardwoods. The description is derived from Arora(1) except where noted. Pleurotus dryinus is fairly common. It is found throughout most of northern North America (Phillips) as well as in Europe. It has been reported from WA (Murrill) and CA (Lincoff(2)). There are collections from BC at the Pacific Forestry Centre and the University of British Columbia, and collections from OR at Oregon State University." [E-flora]

Cap: 4-20cm, convex sometimes becoming flat or slightly depressed when old, margin at first inrolled; "with soft grayish fibrils or scales, but sometimes whitish or in age yellowish"; dry, (Arora), fan-shaped to elongately ear-shaped, (Lincoff(2)), roundish but irregular, often humped, (Brown) [E-flora]
Flesh: very thick, firm; white [E-flora]
Gills: decurrent, fairly close, often veined or forking on the stem; white but sometimes discoloring yellowish when old, (Arora), narrow, with subgills; edges may be serrate, (Schalkwijk-Barendsen) [E-flora]
Stem: 3-10cm x 1-3cm, often short, equal or narrowing downward, "usually off-center but sometimes central", rather tough, solid; whitish, (Arora), usually horizontal, whitish, but becoming yellowish when bruised or with age, (Brown) [E-flora]
Veil: membranous, white to grayish, forming a slight ring on stem "or leaving remnants on cap margin or disappearing entirely", (Arora) [E-flora]
Odor: mild to pungent or fragrant (Arora), pleasant (Phillips) [E-flora]
Taste: pleasant (Phillips), bitter almonds according to Kauffman (Brown) [E-flora]
Spore Deposit: white[E-flora]

COMMENTS: "The thick firm flesh and soft hairs or scales on the capare good fieldmarks; so is the veil when it is visible (see photograph at bottom of p. 135). It might be confused with Lentinus lepideus, which has serrated gills, or Panus strigosus, which is differently colored. P. corticatus, Panus dryinus, and Armillaria dryina are synonyms." [MushDemyst]

Habitat/Range "single or in small groups on hardwoods, usually living, (Arora), July to October (Phillips), fall to winter (Buczacki), summer, fall, winter[E-flora] Solitary or in small groups on hardwoods (usually living); widely distributed but not common. Alder is a favorite host; it is also reported on oak, and I've found it growing locally from the wound of a living madrone, in December." [MushDemyst]

Edible Uses



Pleurotus ostreatus - Oyster Mushroom

Summary: " The Pleurotus ostreatus complex is distinguished by smooth whitish to grayish to brownish caps with shelf-like habit, soft thick flesh, whitish gills, and whitish to lilac spore deposit. Vilgalys(4) have divided the complex in North America into Pleurotus ostreatus (Fr.) P. Kumm., Pleurotus pulmonarius (Fr.) Quel., and Pleurotus populinus O. Hilber & O.K. Miller, and this description is derived from theirs except where indicated. Other features of Pleurotus ostreatus in particular are relatively large, spathulate, scallop-shaped, or mussel-shaped caps, close to crowded gills, lilac to lilac-gray or light purplish vinaceous spore deposit, and spores 7.5-9.5 x 3.2-4 microns. Thorn(3) have shown that this species as well as other Pleurotus and Hohenbuehelia species attack and consume nematodes [roundworms]. The P. ostreatus complex is common in the Pacific Northwest, and includes lilac spored specimens over 15cm wide, at least in BC, but collections used by Vilgalys(4) from the Pacific Northwest are P. pulmonarius and P. populinus. Collections of this species used in the Vilgalys(4) analysis are from ON, AL, AR, AZ, CA, DC, FL, GA, IL, MD, MN, MS, NC, NJ, NY, PA, TN, VA, WI, WV, Czechoslovakia, France and Germany." [E-flora]

Cap: (4)6-15(25)cm wide, convex, spathulate, scallop-shaped to mussel-shaped, margin inrolled becoming nearly flat when old and only slightly inrolled; whitish, yellow, pale yellow to grayish yellow, light tan to dark brown, also drab, light cinnamon drab, cinnamon drab, to light drab near margin, with some caps mostly pale cinnamon-pink; moist when young but never viscid, soon dry; finely white pubescent [downy] to pubescent over the lateral point of attachment to stem, smooth over the rest of the surface [E-flora]
Flesh: up to 1cm or 2cm thick, firm, somewhat fibrous, solid; white[E-flora]
Gills: adnate to mostly decurrent, close to crowded, broad, 0.5-1.5cm, with two tiers of subgills, sometimes forming a reticulum [network] near the point of attachment; dull whitish to pale pinkish buff; edge smooth at first, becoming eroded when old[E-flora]
Stem: (0.5)1-3cm x 0.3-2(3)cm, laterally attached, stocky, nearly equal; dry, white pubescent to strigose at base [E-flora]
Odor: pleasant and anise-like, becoming fungoid and unpleasant in age [E-flora]
I think oyster mushrooms have a peculiar smell, but I would be hard pressed to describe it. An "oyster mushroom smell" is about all I can come up with, but the not-unpleasant odor seems fairly distinctive in the mushroom world.[]
Taste: mild and pleasant in fresh specimens [E-flora]
Spore Deposit: lilac to lilac-gray, to light purplish vinaceous [E-flora]
Similar Species: "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, in the western states Pleurotus pulmonarius grows on conifers as well as Quercus, Lupinus etc. (on hardwoods in the eastern states), (Vilgalys). Caps of P. pulmonarius tend to be smaller and young caps are lung-shaped rather than semicircular (Petersen et al. website). Pleurotus populinus has a buff spore print, subdistant gills, and longer spores, and generally favors Populus and tends to be smaller with a light colored cap, (Vilgalys). Pleurocybella porrigens somewhat similar but smaller, thinner, and white. Panellus serotinus has a yellow stem punctate with brownish scales, gills with ocher yellow colors, and a cap commonly having greenish or violet tones." [E-flora]

COMMENTS: "Pure, pale, and graceful, the oyster mushroom is easily distinguished by its white gills, tender flesh, smooth cap, and shelflike growth habit on wood. The cap color and position of the stem depend to some extent on the location of the fruiting body. When growing out of the side of a log, the stem is lateral or absent, since there is no need to elevate the. cap. When growing from the top of a log, however, the stem can be central, leading to confusion with Clitocybe. The cap is generally darker in sunlight and correspondingly paler in dim surroundings, but distinct color forms also seem to occur, including a brown- capped form that grows on bush lupine along the ocean and a giant thick-fleshed form that is common on cottonwood in inland valleys. In fact, P. ostreatus has long been recognized as a "collective" species, i.e., a group of closely related but distinct forms. Fortunately, they all appear to be edible, so that their exact taxonomy needn't concern you (at least, it doesn't concern me!). Other species: P. sapidus is now regarded as a synonym for P. ostreatus; P. columbinus is a rare species with a bluish- or greenish-tinted cap, but is otherwise very similar; P. cornucopiae grows in dense, upright clusters on woody debris in the Rocky Mountains and probably elsewhere. It has a lined or ridged, nearly central stalk and depressed or funnel-shaped cap that is open (incised) on one side. It is edible when young but often develops a bitter or unpleasant taste in age. For a smaller, thinner, white species growing on conifers, see P. porrigens." [MushDemyst]

"So you think oyster mushrooms or "tree oysters" (Pleurolus ostreatus) always grow on trees? Left: Clusters growing in a treeless field on decomposing coffee beans. Right: A cluster growing out of a kitchen chair. (The owner of the chair claims to be a sloppy eater who unknowingly helped incubate the developing mycelium by sitting in the chair. A fortuitous leak in his roof elicited this crop of oyster mushrooms. He now waters the chair regularly!)" [MushDemyst]

Habitat/Range "single, or more usually in large imbricate [shingled] clusters on the sides of stumps, logs and branches of hardwood trees, less commonly on conifers (Pinus - pine and Abies - true fir), fruiting during cool weather wherever hardwood hosts are found, especially fond of riparian habitat [fall, winter]" [E-flora]

"Occasionally solitary but usually in shelving masses or overlapping rows or columns on hardwood logs and stumps; sometimes also on standing trees, rarely on conifers; common throughout most of the northern hemisphere. Its preferred hosts include elm, cottonwood, alder, and sycamore, but in our area it favors oak and tanoak, producing large crops after the first fall rains and smaller crops thereafter through the spring. I have also seen stupendous fruitings (several hundred pounds!) growing in clusters in a treeless field where crushed coffee beans were dumped. It is easily cultivated on a wide variety of substrates, including compressed sawdust, shredded Time magazines, and presumably coffee grounds. If an "oyster log" is dragged home from the wild and kept moist, it will produce crops regularly." [MushDemyst]
"Forming overlapping shelves or clusters on stumps and logs of hardwoods, uncommon on conifers, from early fall to mid- winter. Pleurotus ostreatus is a member of the "Fog Flora" fruiting sporadically along the coast during the summer." []

Edible Uses

Other Uses

Medicinal Uses

"Oyster mushroom (Pleurotus ostreatus) is extremely delicious as well as conferring various health-giving properties. Traditionally, it has been used to strengthen veins and relax tendons. In China oyster mushroom is indicated for joint and muscle relaxation (Yang & Jong, 1989). A product containing oyster mushroom, called "Tendon-easing powder," is effective in the treatment of lumbago, numbed limbs, and tendon and blood vessel discomfort. In the Czech Republic, extracts have been made from the fruiting bodies as the main ingredient in dietary preparations recommended for prevention of high cholesterol (Opletal, 1993). The dried oyster mushrooms are said to be high in iron, so they are potentially good blood builders. Dose: The recommended dose is 3-9 grams daily." [MM3 Hobbs]


Pleurotus populinus - Aspen Oyster

"Pleurotus populinus is part of the oyster mushroom complex, which is centered around the "true" oyster mushroom, Pleurotus ostreatus. I call Pleurotus populinus the "aspen oyster," since it appears to be limited to the wood of quaking aspen and closely related trees (aspens and cottonwoods in the genus Populus). It is northern and montane, corresponding to the range of the host trees. It is a well established biological species (meaning that it cannot "mate" with the other oysters) supported by DNA evidence. Fortunately for those of us who do not have mycology laboratories at our disposal, its ecology (the relationship to aspen) and even a few morphological features are distinct. The cap is not dark brown, as it sometimes is in Pleurotus ostreatus, and the spore print is always whitish rather than whitish to grayish or lilac. Under the microscope it has longer spores than Pleurotus ostreatus or Pleurotus pulmonarius." []

Summary: "a member of the Pleurotus ostreatus complex (smooth whitish to grayish to brownish caps with shelf-like habit, soft thick flesh, whitish gills, and whitish to lilac spore deposit), and best recognized within it by its whitish to buff spore print, light colored cap, subdistant gills, and larger spores (up to 15 microns long); description from Vilgalys(4) except where noted; collections used in Vilgalys(4) analysis came from BC, ID, and also ON, CO, MD, MI, MT, NY, WI, distribution "similar to that of its aspen host, occurring in most northern states in the east, and throughout the montane and northern regions of western United States", (Vilgalys)" [E-flora]
Cap: 4-6(9)cm wide, convex, oyster-shell-shaped to fan-shaped, the margin inrolled at first; pinkish buff, pinkish gray to ivory white; dry, smooth, pubescent [downy] over the lateral point of attachment [E-flora]
Gills: decurrent over the short point of attachment, subdistant, 2 tiers of subgills, broad, 0.5-1cm broad; nearly white to cream [E-flora]
Stem: 1-1.5cm x 0.6-1cm, "lateral, equal or tapering to a narrow base, white lamellae extending almost to the base that is covered with a white pubescence" [E-flora]
Odor: not distinctive to anise-like [E-flora]
Taste: mild and pleasant [E-flora]
Spore Deposit: buff-colored, not lilac [E-flora]
Similar Species: "Pleurotus ostreatus has lilac spore deposit and tends to be larger, and P. pulmonarius may have lilac spore deposit, both have close to crowded gills and shorter spores, Pleurotus populinus usually lacks the strong brown colors that sometimes characterize P. ostreatus and P. pulmonarius, both of which may however be found on Populus; 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" [E-flora]

Habitat/Range "single to numerous and often imbricate [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, (Vilgalys), spring, summer, fall." [E-flora]

Edible Uses


Pleurotus pulmonarius - Summer Oyster

Above images have not been definitively ID'd to species level.

"The separation of Pleurotus pulmonarius from the infamous "true" oyster mushroom, Pleurotus ostreatus, is based on very good evidence that covers the three "species concepts" most commonly applied to fungi. In the laboratory, Pleurotus pulmonarius cannot "mate" with the other species in the oyster complex, so it is a good biological species. It also represents a fairly distinct morphological species, since it is paler (and frequently smaller) than the brownish Pleurotus ostreatus and appears to develop more of a stem, more of the time. DNA evidence supports Pleurotus pulmonarius as a phylogenetic species and, to top it all off, there is an ecological difference: it appears in warmer weather than Pleurotus ostreatus, which favors cold-weather conditions. Pleurotus populinus is also virtually identical, but it grows only on the wood of Populus species (aspens and cottonwoods). Pleurotus pulmonarius will grow on the wood of virtually any hardwood, including aspens and cottonwoods--in which case the larger spores of Pleurotus populinus will help separate the species." []

Summary: "member of Pleurotus ostreatus complex (smooth whitish to grayish to brownish caps with shelf-like habit, soft thick flesh, whitish gills, and whitish to lilac spore deposit; see Pleurotus ostreatus and SIMILAR); description from Vilgalys(4) except where noted; Li(1) presented evidence in 2005 that this is the so-called phoenix mushroom "referring to the phoenix graph in the logo of the University of Hong Kong, which represents the basidioma of the fungus": almost a billion metric tons of the phoenix mushroom is produced worldwide every year, mostly in mainland China; collections used in Vilgalys(4) analysis came from BC, ID, and also AZ, CA, MD, MI, MN, MT, NC, NH, NY, PA, TN, VA, WI, Germany, Sweden" [E-flora]
Cap: 2.5-9cm, spathulate, oval to conch-shaped, nearly flat when old, margin recurved [curved up] to nearly straight when old; white to grayish white, pinkish brown or light orange brown often with a hint of gray, light brown or brown; dry, dull, bald, "often with shallow surface indentations near the margin and point of attachment" [E-flora]
Flesh: firm, sometimes water-soaked near the cap skin; dull white, "not changing upon bruising or cutting" [E-flora]
Gills: short decurrent to decurrent, close to crowded, with 2 tiers of subgills, gills moderately broad, 0.5-1cm broad, often anastomosing and intervenose along stem; white to slightly cream color when old [E-flora]
Stem: 1-2cm x "8-8 mm wide [sic]", lateral to subcentral; white; "surface covered with irregular shallow ridges that are sometimes intervenose to almost poroid and reticulate", extending from the gills, densely hispid [bristly] to pubescent [downy] over the base at the point of attachment [E-flora]
Odor: pleasant, with a vague anise-like aroma when fresh [E-flora]
Taste: mild at first and pleasant, becoming strongly fungal and eventually putrescent [E-flora]
Spore Deposit: variable, white, yellowish, buff to lavender gray when heavy [E-flora]

Habitat/Range "in imbricate [shingled] clusters, rarely single, on logs, limbs and stumps of conifers at mid-level elevations (1200-3000 m) in the western US, of hardwoods (primarily) in the eastern states. [E-flora] Saprobic; growing in shelf-like clusters on dead and living wood of hardwoods; causing a white rot; beginning in summer (unlike Pleurotus ostreatus) but continuing into fall and winter; widely distributed in North America." []

Edible Uses


Page last modified on Friday, June 30, 2023 8:08 AM