The Complete Guide to Pholiota Adiposa

With its distinctive yellow cap and scaly appearance, Pholiota adiposa is not only a visual delight but also a nutritious one. Packed with protein, fiber, and other essential nutrients, this functional mushroom is an excellent choice for those looking to improve their health.

There isn’t much information about this species due to its confusing taxonomical history—but we’ve done our best to gather everything that could be useful for you. Read on to learn about the history, health benefits, and general facts of Pholiota adiposa.

What is Pholiota adiposa?

Pholiota adiposa, more commonly known as P. adiposa or “chestnut mushroom,” is an edible mushroom native to China, Japan, and Korea. Similarly, it’s present in North America and Europe—although to a lesser extent. Also known as “yellow-cap fungus” and “fat mushroom,” it’s famous for its distinctive yellow color and scaly cap (1) (2).

P. adiposa is a wood rot fungi that grows on deadwood and live willow, poplar, and beech trees. The fruiting bodies appear during the first flushes of autumn, from August to October. Oddly enough, and unlike most other mushrooms, P. adiposa tends to grow several meters above the ground.

Chestnut mushrooms are, like most fungi, very rich in nutritional values and health benefits. Its flavor is rather mild, often resembling smoked meat but with little to no smell. Its texture is meaty but firm—making it the ideal choice for replacing other, more intense-flavored fungi such as shiitakes (3).

How does P. adiposa look?

P. adiposa has a distinct yellow cap measuring 6-9 cm (2.3-3.5 in) with convex edges that flatten out as the mushroom ages. This cap is covered by numerous brown and yellow scales that give it its famous “chestnut” look. Its stipe is rather long, measuring 5-12 cm (2-4.7 in)—this stem is also yellow but often turns brown with age. Its spore print is also brown.

Like most wood rot mushrooms, P. adiposa grows in dense clusters. It’s common to find these clusters high up on the trunks of certain trees. Yet, they can also grow on the ground if the substrate is appropriate enough (2).

What are the varieties of Pholiota adiposa?

Pholiota adiposa has a complicated taxonomy—but the general consensus is that this species doesn’t have any varieties. However, there has been a lot of confusion (even among mycologists) with other lookalike species. These include Pholiota aurivella, Pholiota jahnii, and Pholiota limonella.

P. aurivella, in particular, has caused a lot of trouble, often being grouped with P. adiposa into a single species. However, P. aurivella differs from P. adiposa in that it only grows on willows, and its scales are more numerous and thick.

P. jahnii is also a lookalike, but it grows at the base of trees instead of several meters above the ground. Another noticeable difference is that its scales are darker and more numerous.

P. limonella is like the little brother of P. adiposa—smaller, less impressive, but still trying to keep up with the family reputation. P. limonella is arguably the most identical lookalike, but it’s smaller in size and its spores are much narrower. P. limonella also prefers other trees to grow on, such as black alders and spruces (3).

These three species are sometimes mislabeled as varieties by amateur mycologists and wildcrafters. However, experts suggest that they are not edible, so telling them apart is essential if you don’t want to get an upset stomach. P. aurivella may even be poisonous—but more research is needed to confirm this.

History of chestnut mushrooms

Unfortunately, there’s no research available on the history of P. adiposa. However, that doesn’t mean that ancient cultures didn’t consume this mushroom. For example, the Ancient Chinese considered mushrooms to be an elixir of life, and there are several mycology records that date back as far as 1245 (4).

At that time, species weren’t even close to being defined—so these books only provide loose descriptions of specific specimens. It’s possible that some of them refer to P. adiposa, but sadly, there’s no concrete proof for this.

As for its culinary history, there aren’t any specific records detailing when it became part of most countries’ cuisines. In fact, many researchers still claim that this mushroom is inedible—the origin of this belief probably has to do with P. adiposa’s similarity with P. aurivella.

The first taxonomical record of P. adiposa dates back to 1786 when it was first described by German naturalist August Batch. He originally placed it under the Agaricus genus—a biology classification that groups similar species. This was later corrected in 1871 by Paul Kummer, who transferred it to the genus Pholiota.

Yet, in 1915, the concept of P. adiposa grew to describe another species (P. jahnii). This confusion wasn’t cleared until 1987, meaning these two species were considered synonymy for almost a century (3).

Since then, the taxonomy of P. adiposa has remained rather still, but the confusion caused by this misclassification is still present in the scientific community.

Health benefits of Pholiota adiposa

Pholiota adiposa is part of what’s called medicinal mushrooms or functional mushrooms—fungi that provide unique medicinal and nutritional properties. Also called nutraceuticals, these foods include several other species, including Agaricus bisporus (button mushroom) and Pleurotus ostreatus (oyster mushroom).

At first sight, P. adiposa may not seem too impressive regarding its nutritional balance. It’s high in protein, ash, and fiber while also being low in fat. This is common in most mushrooms—so no surprises here, right?

Well, where this mushroom really shines is in its micronutrients, which not only include minerals and vitamins but also several other beneficial compounds. For example, P. adiposa contains amino acids, polysaccharides, and ergosterol. These compounds can be found both in the fruiting bodies and in the mycelium (5).

There have been several studies that show the health benefits of P. adiposa. For example, a 2013 article studied the effect of adenosine extracted from P. adiposa on certain cell components. Surprisingly, the results show that this compound can protect the cardiovascular system, have potent anti-inflammatory effects, and boost the immune system (6).

Another study performed in 2003 tested P. adiposa against several bacteria that cause human infections. Researchers found that several of these pathogens were sensitive to P. adiposa, including Esterichia Coli and Staphylococcus aureus (7).

There are dozens of other studies demonstrating the medicinal benefits of chestnut mushrooms. In summary, the beneficial properties of P. adiposa include, but are not limited to (8):

• Antitumor
• Antihypertensive
• Antimicrobial
• Antifatigue
• Antihyperlipidemic
• Antioxidant

In fact, P. adiposa is being studied as a possible treatment for AIDS thanks to a compound called HEB, which shows significant anti-HIV activities. However, you should never take P. adiposa for medicinal purposes without the supervision of a doctor (8).

Where do chestnut mushrooms grow?

The distribution of this species is somewhat unclear due to its confusion with other Pholiota species. Most experts agree that this fungus is native to China, Japan, and Korea. Supposedly, it’s also possible to find it (to a lesser extent) in North America and Europe (1) (2) (3).

P. adiposa is commonly found growing in rotting wood, such as dead branches or timber. While they usually grow several meters above the ground, it’s also possible to find them on fallen pieces of wood.

Chestnut mushrooms may also grow on other substrates, such as sawdust—although it may need to be deliberately inoculated for this to happen. This approach (called sawdust spawn) is a common way to sell P. adiposa “seeds.”

What is ethical wildcrafting?

Wildcrafting is the practice of harvesting natural resources (such as fungi) for medicinal purposes. It’s similar to foraging, but the key difference is that the latter refers to harvesting for eating.

Due to its many beneficial properties, P. adiposa is a common target for enthusiastic wildcrafters. While this species is not particularly endangered, you should always consider a few ethical guidelines while harvesting it. These include:

• Getting to know the local species beforehand and taking note of any endangered ones
• Picking the fruiting bodies gently to avoid damaging the rest of the patch
• Not taking more than you need
• Not sharing the location of patches with other people
• Performing deep research on the species you’re seeking
• Carrying a field guide to distinguish different species from one another
• Asking for the land owner’s permission (if you’re wildcrafting on private land)
• Checking your local harvesting laws (if you’re wildcrafting on public land)

Practicing ethical wildcrafting will go a long way in keeping the species safe in your local area. If you’re new to mushroom picking, we recommend looking for a harvesting group that can teach you how to wildcraft ethically and responsibly. It’s a great way to do your part to keep fungi populations flourishing!

Is it safe to wildcraft for P. adiposa?

Mushroom picking always carries some risks. While most of the lookalikes of P. adiposa aren’t poisonous, most of them are inedible. Eating the wrong mushroom could lead to indigestion and other gastric problems.

Furthermore, wild mushrooms can potentially contain toxins from the environment. As such, you should never eat them raw—even if you’re 100% positive that you picked P. adiposa.

We love mushrooms as much as anyone else, so we understand that harvesters can sometimes be overconfident in their ability to distinguish different species. However, even the most experienced mycologists regularly confuse P. adiposa with its lookalikes—so make sure you proceed with caution.

How do you take Pholiota adiposa?

Like most edible mushrooms, there isn’t a specific way to take P. adiposa. In fact, due to the confusion regarding its edibility, there aren’t a lot of recipes that call specifically for this species. Still, you can add them to any meal you imagine—chestnut mushrooms are versatile due to their mild flavor.

Ideally, you should cook P. adiposa by sautéeing or simmering the mushrooms to avoid losing nutrients. However, people who don’t usually eat mushrooms may start with easier cooking methods such as boiling (9). 

Then, you can add them to pretty much any plate. Soups, salads, and stews are perfect for P. adiposa—even more so if you’re trying to replace meat. Don’t be afraid to experiment with mushroom combinations as well. P. adiposa works really well with other, more flavorful species, such as pink oyster mushrooms.

Pholiota adiposa: Incredibly confusing, incredibly beneficial

Pholiota adiposa is an edible fungus primarily found in China and other Asian countries. It has confused mycologists for centuries, but recent research shows that it can have amazing medicinal properties. Plus, due to its mild flavor, P. adiposa is the perfect addition to almost any plate that allows some flexibility.

If you want to find out about other types of mushrooms or how to grow mushrooms through mushroom cultivation, make sure to keep up on shroomer. Here, you’ll find all the details you need about psychedelic and functional fungi from all over the world, along with the latest news on medicinal research on edible mushrooms.

References

1. Zhan Bin Wang, Hong Yun Xu, De Hai Li, Jing Jie Wang. “The Biological Characteristics and its Sequence Analysis of Pholiota adiposa.” Advanced Materials Research 518-523 (2012): 5371-5375. https://doi.org/10.4028/www.scientific.net/AMR.518-523.5371
2. Alexander H. Smith, L.R. Hesler, “Section Adiposae Konrad & Maublanc,“ in The North American Species of Pholiota (1968), 180
3. Jan Holec. “The taxonomy of Pholiota aurivella and Pholiota adiposa - a return to Batsch and Fries.” Czech Mycology 50 (3) (1998), 201-222. http://www.czechmycology.org/_cm/CM50306.pdf
4. Wang Yun-Chang. “Mycology in ancient China.” Mycologist 1 (2) (1987), 59-61. https://doi.org/10.1016/S0269-915X(87)80040-X
5. Hui Feng-li, Wei Ming-hui, Liou Zheng. “Analysis of Nutritional Components in the Fruitbodies of Pholiota adiposa.” CNKI (n. d.). http://en.cnki.com.cn/article_en/cjfdtotal-syjb200304005.htm
6. Chang Rong Wang, Wen Tao Qiao, Ye Ni Zhang, Fang Liu. “Effects of Adenosine Extract from Pholiota adiposa (Fr.) Quel on mRNA Expressions of Superoxide Dismutase and Immunomodulatory Cytokines.” Molecules 18 (2) (2013): 1775-1782. https://doi.org/10.3390/molecules18021775
7. Basaran Dulger. “Antimicrobial activity of the macrofungus Pholiota adiposa.” Fitoterapia 75 (3-4) (2004): 395-397. https://doi.org/10.1016/j.fitote.2004.01.005
8. Chang Rong Wang, Rong Zhou, Tzi Bun Ng, Jack Ho Wong, Wen Tao Qiao, Fang Liu. “First report on isolation of methyl gallate with antioxidant, anti-HIV-1 and HIV-1 enzyme inhibitory activities from a mushroom (Pholiota adiposa).” Environmental toxicology and pharmacology 37 (2) (2014): 626-637. https://doi.org/10.1016/j.etap.2014.01.023

The Nutrition Source. “Mushrooms,” March 2, 2022. https://www.hsph.harvard.edu/nutritionsource/food-features/mushrooms/