Man in forest with large mushroom

Written by Timo Mendez - Published on 28 July, 2023

Yellow Oyster Mushrooms growing from base of tree

Photo by majorwarning

For mushroom enthusiasts like myself, mushrooms aren’t just an exciting food item; they’re a downright obsession. We ponder about them under almost any circumstance and will talk your ear off about them endlessly. Chances are, if you’re reading this, you probably know someone who fits this description (might be you!).

While I’m the first to admit we can sometimes be a bit fungi-centric, there is no doubt in my mind that mushrooms are amazing and intoxicatingly fascinating. They’re not only delicious, nutritional, and even medicinal, but they can lend so much more to humanity than most of us even consider.

While different branches of the fungal world interest different people, for me, one of the most spectacular is all of the wild edible mushrooms that exist in nature. The big, the small, the rare, and the common ones; they all hold a special place in my heart.

One of my favorites which is often overlooked by gourmet foragers is none other than the emblematic oyster mushroom, or should I say “Oyster Mushrooms”. That’s because there are dozens of different species of oyster mushrooms in nature and hundreds of cultivars in cultivation.

In this article, we are going to discuss everything you need to know to start identifying and foraging your very own Oyster Mushrooms. We’ll discuss their ecology, their distribution, their tree hosts, and how to properly (and confidently) identify them. We’ll also be discussing some of their look-alikes and how to harvest/cook them properly.

What is an Oyster Mushroom?

In A Nut-Shell: Oyster Mushrooms are a group of fungi that are classified in the genus Pleurotus. There are more than 30 species in nature some of which are widely cultivated and commercialized. They are decomposers meaning they take complex organic materials, break them down, and consume them as energy. 

This makes them important players in the ecological nutrient cycle, where they take locked-up nutrients and make them accessible to other organisms such as plants. They come in a wide array of colors, shapes, and sizes, and can often be identified by their form, smell, and gills that run down the stem.

The Bigger Picture

From tropical rainforests to desert landscapes, Oyster Mushrooms are some of the world's most widely distributed groups of organisms. They are voracious, adaptable, and omnipresent. They’re known to consume almost everything and anything; from toxic waste, unrefined oil, cigarette butts, and even your spent coffee grounds. There aren’t many carbon-based things Oyster Mushrooms won’t eat given the right conditions.

No one knows this better than mushroom farmers themselves. Oyster Mushrooms fall into their own class of “easy-to-grow” mushrooms because of their ability to eat anything and withstand adverse conditions. They can be grown on straw, agricultural waste, wood, and almost anything you can think of. Meanwhile, many other cultivated mushrooms are much more picky! P.S. While they are easy to grow, this doesn’t mean successfully farming them on a commercial scale is easy! Because it's not!

How To Identify Oyster Mushrooms

As previously mentioned, there are more than 30 different species of Oyster Mushrooms. These vary in size, shape, texture, color, and almost anything you can think of. There are several features though that can help you key in the identification.

  • They grow from woody debris. These can be logs, branches, and in some cases even smaller sticks. You won’t ever see Oysters growing directly from the ground. In most cases Oyster Mushrooms grow from hardwoods and only rarely will you find them on conifers.
  • They have decurrent gills. This means that the gills seamlessly run down the stem of the mushroom.
  • They often have a “pleurotoid” structure. This is the shape of oyster mushrooms with an off-centered stem that is angled downwards, and a semi-circular or kidney-bean-shaped cap.
  • They have significant stems. Other lookalikes like “Oysterlings” in the genus Crepidopus have no stems or barely a little nub.
  • They have a distinctive smell that is slightly reminiscent of the ocean.
  • The cap margins are inrolled towards the inside when young and eventually unfurl upwards

Diversity of Oyster Mushrooms

Below there is information regarding a few different species of Oyster Mushrooms you can find in the wild. This list includes some of the most common species as well as some particularly curious ones! 

The Common Oyster Mushroom (Pleurotus ostreatus)

This is the most common oyster mushroom out there. Many different cultivated varieties are derived from this species, such as White Oysters, Grey Oysters, and others. In reality, this species likely is a “complex” of different species that have yet to be thoroughly identified and distinguished as separate species by scientists. In the wild, this species is often white although it can be naturally gray.

Common oyster growing from tree trunk

Photo by Jean-Pol GRANDMONT

Oyster Mushroom growing on fallen log

Photo by dallenstein

Australian Dark Oyster (Pleurotus purpureo-olivaceus)

This is an oyster mushroom native to Australia and New Zealand. It is one of the most common oyster mushrooms in these regions and typically grows on Nothofagus. It has a dark cap and grayish gills but otherwise looks just like a regular oyster.

Dark oyster mushroom growing on fallen log

Photo by David Hera

Underside of dark oyster mushroom

Photo by Reiner Richter

Brown Oyster Mushrooms (Pleurotus australis)

This is another Oyster Mushroom native to Australia and New Zealand. It has a brown-gray cap and white gills. Often it only has a very minute stem and may have cracking on the cap during dry weather.

hand holding brown oyster in the woods

Photo by Jacqui Geux

Pink Oyster Mushrooms (Pleurotus djamor)

This is a well-known cultivated species that is stunning. and pink in color! Has all of the typical features of any oyster mushroom, just in an outstanding pink color. This mushroom grows mostly in warm tropical climates. There are also white morphs of this species!

hand holding Pink Oyster mushroom

Photo by Cajá-manga

The Tuber Oyster (Pleurotus tuber-regium)

Ok, so this is a new one even to me and it’s pretty dang interesting. This Oyster Mushroom is native to South Africa, India, and Australasia and is super unique because it makes a tuber-like structure inside the wood it is rotting. These are dense masses of mycelium called sclerotia that act as storage organs from which the mushrooms are produced. It appears that not only the mushroom is edible, but the fungal tubers as well! This is one for the bucket list.

Regarding its identification, it's a bit different than the typical oyster mushroom. It has a central stem and seems to grow its cap in a funnel-like shape. The margins of the cap also stay enrolled, even once fully mature. The top of the cap is gray, the gills are white, and the stem is also gray.

Tuber Oyster mushroom growing on forest floor

Photo by minx97

Summer Oyster Mushroom (Pleurotus pulmonarius)

This is a white oyster mushroom that looks a lot like the classic Oyster other than a few key differences. It is much paler in color, has a more developed stem, and tends to grow in summer or warmer climates.

summer oysters growing on fallen nwood

Photo by Alan Rockafeller

Golden Oyster (Pleurotus citrinopileatus)

This is by far one of the most beautiful species of Oyster Mushroom. Its golden-yellow and clustered growth makes it incredibly beautiful, both in the wild and in cultivation. Interestingly, this species is invasive in the Eastern United States and is believed to have negative impacts on the diversity of native wood-rotting fungi and also impact the nutrient cycle. 

Yellow Oyster Mushroom growing on base of living tree

Photo by rdegeer

Abalone Oyster Mushroom (Pleurotus cystidiosus)

Okay, so this is a rather average Oyster Mushroom from North America and Asia except it has one stunningly weird exception. This species makes rather normal-shaped Oyster mushrooms but on top of this, it is known to make bizarre a-sexual reproductive structures known as anamorphs. For a long time, these anamorphs were thought to be a separate species altogether. 

Mushroom growing on bark

Anamorphs of the Abalone Oyster Mushroom. Photo by Chael Thomas

Mushroom dgrowing from wood

Photo by Brett Jackson

The Agave Oyster Mushroom (Pleurotus opuntia)

This is a personal favorite of mine and worth a mention, although you won’t find it unless you’re mushroom hunting in Mexico or Central America. This is an oyster mushroom that grows on the base of Agaves aka the cactus from which tequila is made! It rots the core of the plant which contains the sweet delicious sugars that can be made into sweetener or alcoholic beverages!

Agave Oyster Mushroom fruiting

Photo by Timo Mendez

Other Oyster Mushroom Species

  • Aspen Oyster Mushroom (Pleurotus populinus)
  • Lynx Paw Oyster (Pleurotus levis)
  • Veiled Oyster (Pleurotus dryinus)
  • King Trumpet Mushroom (Pleurotus eryngii)
  • Branching Oyster (Pleurotus cornucopiae)
  • Giant Oyster (Pleurotus giganteus)
  • Smith's Oyster (Pleurotus smithii)
  • Blue Oyster Mushroom (Pleurotus columbiana)
  • Fir Oyster (Pleurotus abieticola)
  • Florida Oyster Mushroom (Pleurotus floridanus)
  • White Ferula Mushroom (Pleurotus nebrodensis)

Oyster Mushroom Look-a-Likes

There are 2 main “look-a-likes” for Oyster Mushrooms that are good to know if you have any doubts about identification.

Oysterlings (Crepidotus sp.)

These are small mushrooms that grow directly from wood, just like oysters. They have a similar shape, and color, and can be easily mistaken. They are thankfully not toxic, but they might not be as delicious! The main way to tell these apart are;

  • They’re always relatively small, just a couple of centimeters across.
  • They have almost no stem or just a tiny little nub.
  • Certain species have fine hairs or a fuzzy texture on the top of the cap.

Gill side of Oysterlings (Crepidotus sp.)

Photo by Timo Mendez

Angel Wings (Pleurocybella porrigens)

Okay, so this is the one most people worry about when they’re harvesting Oyster Mushrooms. There are some horror stories regarding their toxicity, but it's not clear how toxic they are or if all the varieties across the world are toxic. So far, the only reports of intoxication are from Japan where this was a highly valued edible mushroom up until about 2004.

This is because in 2004 numerous reports of intoxications seemed to have been linked to this mushroom. The side effects included degenerative diseases that affected both the kidney and the brain. In some individuals, largely those with preexisting conditions, the toxicity was fatal. Despite there being a tradition of consuming this mushroom in Japan, authorities now recommend against the consumption of this mushroom.

While this is pretty shocking to many people, don’t let this scare you off from consuming a foraged oyster mushroom. Remember, this was a very popular edible mushroom in Japan for centuries. Essentially, it is an edible mushroom its just that a very small percentage of people may have negative reactions to it. The only reason there were reports of illnesses is because lots and lots of people were consuming them! Outside of Japan, there have been no intoxications reported on this mushroom.

How To Differentiate Angel Wings From Oyster Mushrooms

  • Pale white color, typically lighter than most oyster mushrooms.
  • Often they have very small stems and gills that run almost down the entire stem.
  • Angel Wings have highly concave or folded caps while Oysters are flatter (although not always). This folded “taco-shell” style growth is very indicative of Angel Wings!

Angel WingMushroom growing on log

Photo by Bethsheila Kent

Angel Wing Mushroom

Photo by Carita Bergman

Harvesting and Cooking Oyster Mushrooms

When it comes to harvesting Oyster Mushrooms, I prefer to cut the mushrooms directly from the log. This way I don’t have the dirty stem butt which I’m not going to eat anyways. If you prefer to pick and then cut, that’s fine too! Avoid harvesting from contaminated areas where mushrooms (and their substrates) could contain heavy metals, pesticides, car exhaust, or other hazardous compounds. Leave some behind for critters and other pickers as well!

When it comes to cooking, the number one rule is to eat them quickly. That's because wild oyster mushrooms almost always come "pre-inoculated" with the eggs of fungus gnats inside of them. Waiting even just a couple of days after harvesting could be enough time for those eggs to turn into squirming larvae. While the larvae are perfectly edible, they do reduce the quality of the mushrooms significantly. Plus, they gross a lot of people out.

You can cook oysters in any way possible. I love to take the large clusters and fry them whole with oil, garlic, and a bit of onion. This way they come out extremely meaty and delicious. Serve them with lime and whatever other dishes you have in mind. Delicious!

Another one of my favorites is to simply pass them through an egg wash and then bread them. Lay them out on an oiled baking sheet, drizzle some more oil on top, and bake until crispy! These come out like chicken nuggets and are so delicious even the kids will eat them up.

Other than these recipes you can cook them in any way you imagine. Stews, soups, curries, stir-fries, and so much more. If you want to preserve the flavor of the mushroom, I recommend frying them up separately with just a bit of garlic and parsley and then serving them as a garnish. Delicious!

Final Thoughts

Oyster Mushrooms go way back to my first experiences with wild mushrooms. I remember my older brother brought a bunch back from a hiking trip to the coast, way before I even knew anything about edible mushrooms. I was doubtful, thinking that for all he knows, he may have harvested a deadly toxic mushroom. Only after doing some personal research and still, with hesitance did I finally end up trying them. They were delicious.

Thinking back to it now, it's funny to think how mushroom-phobic I was. I think this is actually how most people in the “Western” world are when it comes to mushrooms. They think most mushrooms are toxic, and that only few and far between are edible. The truth is, it's the other way around!

This being said, if you have any doubt in your mind regarding the identity of a mushroom, try and contact a local expert. There are also countless Facebook identification groups, oftentimes groups for your local region too. This is a great place to go if you don’t know any experts personally. If you have doubts, can’t find an expert, and don’t feel confident enough to eat them, then don’t! It won’t be worth the anxiety, despite it probably being a perfectly safe mushroom.

The platform INaturalist is also great for uploading pictures and seeing if any regional experts on there can give you a hand with the ID. The explore feature can also help guide you to regions where Oyster mushrooms (and other edible mushrooms) have been found before. It's worth checking out!

Anyhow, happy hunting, and best of luck out there!