Pseudoinonotus dryadeus

August 29, 2022

Good evening, friends,

This week’s mushroom is the oak bracket or the weeping polypore (not to be confused with the oak polypore) – and more formally known as Pseudoinonotus dryadeus. I was surprised to find a mushroom of this magnitude growing in spite of the arid conditions that have plagued the region all summer. It seemed to have found a nice microclimate amongst the moist heartwood of this large oak when I happened upon this mushroom on 8/1/2022.

Fun Facts

An interesting note about the etymology is that dryad – which is a wood nymph in greek mythology – actually means “oak” in Ancient Greek. Pseudo means “false” while ino- is fiber-like and –ot is ear-likeThe sum of the parts here is a false fibrous ear-like mushroom on oak. Alright.

I’ll also contribute an anecdote. Just a few hours before I stumbled upon this mushroom, Ciara woke up with a gnarly sore throat and other cold-like symptoms – she worried it might be strep (fortunately, it wasn’t). Figuring I might be a day or two out from a similar fate, I was concerned. Perhaps the wood nymphs sensed this and that’s why they intended for me to stumble upon this handsome mushroom. Upon closer examination I saw the guttation – the liquid exudate on some polypores, pictured above – and remembered that it can contain novel antimicrobial and antibiotic compounds (I wrote about it in the Abortiporus biennis edition of MM). Now brace yourself folks because what happens next might alarm you. I did a touch of due diligence by scrolling through this PubMed study before using my tongue to swab up all the available liquid on these saturated brackets. It was quite acidic, but I made sure to consume enough to coat the back of my throat. I am happy to report that not only did I survive, but I never got any cold-like symptoms – not even a tickle in my throat. Whether it was the guttation, the placebo effect, something else, or a combination of the three – there may have been some method to my madness.


P. dryadeus is saprobic, growing on oak (and very rarely other species of hardwood), but out west it will grow on conifers – specifically fir trees. It grows summer through fall in North America and Europe. The fungus causes a butt-rot, similar to the lighter colored chicken of the woods, where it consumes the dead wood at the base of tree trunks. They’re considered parasitic, but from my understanding they’re digesting the non-functional xylem cells that were formerly used to transport water, but now mostly serve as structural support. I think the argument can be made that they’re helping recycle carbon back into the environment, but perhaps that isn’t mutually exclusive with being parasitic. So little is known about these mushrooms that it’s fun to theorize about what they’re actually doing in the environment.

The white pore surface turned brown when bruised. The height of all the fruiting bodies spanned eighteen inches and the mushroom is listed as inedible. I returned today to capture how they’ve aged over the past month. See below.

It’s now being digested by bacteria and other fungi, but perhaps the novel compounds in the guttation, and presumably in the fruiting bodies, are allowing it to still exist and retain shape. In fact, it looks like it might’ve grown a new, smaller pore surface on some of the brackets below. That’s at least my hypothesis, but it could also be something else, maybe an entirely different species of fungus. Regardless, neat to see.

I’m gonna level with you gang, coming home to such arid conditions has me kind of bummed out. Almost all the birch trees at Manitou have dropped their leaves, the tulips have been struggling too, but the oaks seem to be the most resilient. They’re still green a nice, deep green – perhaps due to their robust mycorrhizal associations. Let’s hope for a washout of a September,

1) Kuo, M. (2010, March). Inonotus dryadeus. Retrieved from the MushroomExpert.Com Web site:
3) Cateni F, Zacchigna M, Altieri T, Procida G, Cichelli A. Antioxidant Properties of Oak Bracket Mushroom, Pseudoinonotus dryadeus (Higher Basidiomycetes): A Mycochemical Study. Int J Med Mushrooms. 2015;17(7):627-37. doi: 10.1615/intjmedmushrooms.v17.i7.30. PMID: 26559697.