This is a fairly common question I receive, usually accompanied by a picture similar to the one shown here. It’s a good question indeed, and it’s one that I would like to explore beyond a simple “Yes” or “No” answer (spoiler alert: the answer is “No”).
In my early mushrooming days, it was the chaga fungus that had me most excited (don’t get me wrong, I’m still bedazzled). I remember exploring the hardwood forests near Pittsburgh (not exactly an ideal habitat for chaga) in search of this medicinal marvel, and discovering what I thought were potential candidates. I’d perceive one far in the distance and immediately scurry to the spot. Standing under the darkened mass, hoping my search yielded success, I’d wonder, “Is this chaga?”
It wasn’t.
Rather, the abnormal growth that had myself (and countless others, judging by requests on identification forums) fooled was a tree burl resembling the one pictured above. Through the years, my mushrooming skills have improved to the point where no confusion remains on this matter. I have encountered chaga dozens of times during my hikes through the forests of Pennsylvania, I have harvested it on numerous occasions, and I use the fungus as part of my primary medicinal strategy.
Still, there are many individuals who may find it confusing to discern between the two, and I understand. They kinda-sorta look like one another.
To answer the original question proposed in this article’s title, I’d like to further explore the differences, both superficially and functionally, between tree burls and the chaga mushroom.
Tree burl
Sorry, not chaga.
A burl is an outward growth on a tree usually attributed to environmental stress, whether it be physical trauma, an insect, fungus, or even pollutants. Burls can be made up of numerous buds that would typically develop into new shoots, but instead they remain dormant.
Whatever their true cause, burls are not inherently detrimental to the tree. Rather, as trees mature, so do their burls, which develop beautiful patterns and colors that are prized by furniture makers and wood turners.
Unfortunately, burl poaching is a common practice especially in the old growth redwood forests, where burls are illegally harvested and sold for large profits. Harvesting burls from living trees can leave the trees more susceptible to infection and disease, though in many cases the tress are able to heal themselves.
It’s important to understand that a burl is not a fungus, while chaga is. A burl is simply an outgrowth of the tree, meaning the tree’s bark extends to include the burl. The two are not necessarily separate entities.
While the colors may vary depending on the species, burls are usually the same color, if not a bit darker, than the color of its tree. Contrast this to chaga, which usually forms as a blackened crust (on its outside), and appears as a distinct entity on its host tree.
While burls can form on numerous tree species, I encounter them most frequently on oak trees (Quercus spp.) in Western Pennsylvania.
Chaga (Inonotus obliquus)
Yes, this is chaga.
Upon first glance, it’s hard to imagine that this fungus would serve any purpose in benefiting human health. Centuries of traditional use and current research, however, suppress that skepticism, if only by a little.
Chaga is a sterile fungal body usually found on birch trees, though also rarely found on elm, beech, and hornbeam. Its outer material is usually black, brittle, and cracked, while its interior is golden-orange and cork-like.
Note the black, cracked outer appearance and the orange interior (visible at its point of attachment to the tree).
Chaga forms over several years within the tree and eventually erupts through the bark, pushing itself out from within. Thus, it is a distinct species from its host tree, and appears as such.
Notice how distinct chaga looks from its host tree (a yellow birch, Betula alleghaniensis).
To distinguish chaga from a tree burl, ask yourself these questions:
- Is this the right ecosystem for chaga? Chaga usually grows in the circumpolar boreal deciduous forests.
- On which tree is it growing? Chaga grows almost exclusively on birch, though as stated previously, it has been found rarely on elm, beech, and hornbeam.
- What color is it? The outer surface of chaga is cracked, brittle, and relatively black (if not rather dark). A tree burl’s color resembles its host tree, perhaps a bit darker.
- What color is the interior? I don’t recommend haphazardly damaging formations on trees, though sometimes the interior color can be seen naturally without any effort, or simply by removing a small piece by hand. The interior of chaga is an unmistakable golden-orange color (see image below).
- Does the specimen appear to be a separate species, distinct from its host tree? If so, it may be chaga. If the specimen appears to be an extension of the tree, bark and all, you may be looking at a burl.
- Is the growth phallic in nature, or rounded? Chaga usually grows as a phallic, cone-like extension. Tree burls are generally rounded outgrowths. These are shape generalizations for both, as appearances can vary widely, though the majority of chaga fungi and tree burls I’ve seen fit these characteristics.
Note the orange interior amadou of chaga — corky to the touch when fresh.
Having run through these questions, you can feel more confident in your identification of the chaga fungus. If you still harbor some confusion, feel free to send me a photograph and description of your unknown specimen, and I will be happy to assist in identification.
And oh yes, one final note: chaga fungi and tree burls are remarkable sights to view in nature, though both are prone to over-harvesting. Medicine can be made from chaga, and intricate woodwork can be produced from burls. If harvesting either, do so with the utmost intention while inflicting the least amount of harm. It makes the world a better place for everyone!
Thanks for reading, and as always … happy foraging!
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—Adam Haritan
Wild Foodism 
I have a Chaga identification question. Im completely puzzled with this specimen. could you please send me an email an I will be happy to attach photos to a reply.
Thank you
What does the chaga pill look like?
I am pretty confident we have found chaga, about 15 feet up on a yellow birch. Just don’t want to consume much in case we have found a toxic distant cousin! How could I send you a picture for a second set of eyes? Sure looks like the pictures and as. Tea tastes great!
Great read. I have been on the hunt for wild chaga and keep coming across a growth that is very similair but it is on a tree that looks like gray birch maybe. Would like to send some pictures to see if you can help.
Have you every seen chaga with a grey mushroom like bottom. The top and inside looks like chaga but the bottom throws me off. It was found on a very old white birch.
That is most likely a.birch Polypore fungus.
I agree with Liz, I just found a bunch of Fomes fomentarius and I could imagine it looking just like you describe. For instance, and Adam can correct if there are better ways to differentiate: fomentarius and I think other birch polypores have zones in the outside (bands of color that may have all turned dark gray to black in your find) whereas chaga will not have those ring it band looking zones. Also if that confusing bottom part of the mushroom has little dots those are pores which chaga does not have.
Does Chaga have a scent? I bought Chaga from 2 different companies, one has a strong scent and the other did not. Which one is real Chaga?
Thanks!
Hello! Wondering if you might know what is growing on our white birch branches. Many clumps or bunches of what look like small black crunchy berries. No growth on the trunk just on smaller branches growing off larger branches. The tree is about 27 years old. Just noticing it in the last few years. Still hanging there over winter.
Thank you!
As always, incredibly informative and laid out in a simple yet thorough manner. You are the best, dude! Thank you so much. I will have to start hunting and asking myself those questions…
Mushrooms have interested me especially medicinal mushrooms
Hi
I’m very confused, I live in south Africa, in the lowveld, we never see snow and regularly get temperatures of 28°c. We have a donga that has many mushrooms growing in it. I have found what we believe to be rieshi and I think chaga but the chaga is on a pine tree. Which then makes me think it isn’t a chaga. I would love to be able to send you some pictures and ask you please to help me identify these mushrooms. If you could take the time.
Thank you
Regards
So Chaga does grow in Pennsvania?
I live in the Pocono Mountains and have
Been looking for Chaga. Wasn’t quite
sure it would grow this far south or not .
You’ve actually found it here in Pa?
We have a fungus that grows in the yard every year. We do have all the trees you describe but this grows from the ground. I do have pics!
Cool post, do you mind if I link to it from my new blog/tea shop?
Its called Lovely Tea Teas? Thanks in advance –
Oliver aka Mr Tea
how to I send you a picture?
I am kicking myself in the butt right now! I have seen this SO many times and thought that it was some kind of strange lightning strike on the tree. It does have a “burnt” look to it! I’m always out in the woods, working on my plant/tree identification skills, so you’d think I would have known it was chaga! Although, I haven’t done much research on fungi, my dad talks about chaga all the time and he’s a bit of a mushroom “expert”.
Thank you for your information sharing as I am a newbie of 2 yes and still feel like I haven’t learned yet a pinch of what’s out there to learn. Chaga is very interesting and will be a part of my daily routine. God bless.
Very helpful. I keep looking but I keep finding burls. These photos and the description puts the visual in better perspective for me moving forward.
Thanks!
I have been harvesting chaga for about two years now and always from the birch tree. However, I am finding what I believe is also chaga on poplar (or possibly elm) trees. I have been told that only chaga from birch is usable. Do you harvest and use chaga from poplars? I live in Northwestern Ontario, Canada
So when grinding this chaga up to make into a tea do you use the whole entire thing or do you just use the inside or just the outside???
And also can you use it as a supplement for triple antibiotic ointment and if so do you just apply it straight to the wound or what just a question I kind of had you can help me answer that I’d be much obliged please and thank you sir???!!!
Wondering if you could help me identify this as chaga? I’m going to send an email to the address you posted. Thanks!!
Great blog! I am excited to find you as I Learn My Land. I live off grid on 50 amazing acres in north central Maine. Have already discover much! Lots more to go…
I’m not sure I completely agree with this. I have a number of oak trees on my property that have these “burls” but their interior is orange and they consume and kill the tree. The tree does not just keep growing. Some of the trees are infected all over with these growths and as limbs succumb, they fall off to the ground. Further research on the net will tell you that chaga can grow on oak but not include the same medicinal ingredients. I’d be happy to provide video or photographs of what I’m seeing if you like.
I was hoping to identify either burl or chaga if I can send or post a photo?
It’s in NC, (probably not usual) in a forested area around homes with Birch trees around but this is not a birch that has the specimen.
I would like to know if chaga is edible from black birch
Thank you 🌍🤙🏽
I have been harvesting chaga for 14 months. I harvest solely for my own use. I also give some to friends as well as members of my family. Today, on November 27, 2019, in Quebec, Canada I believe that I have seen a chaga on a tree other than birches. I have seen it in a beech. How can I send you a picture with a view to confirming whether or not it is, indeed, chaga.
Sorry I have a second question. Is chaga from a beech tree as good to consume as chaga from birch trees? Thak you!
By the way I have read all the included articles. It’s very interesting,
I believe I found a number of chaga on a clump of grey birch. All the fungus are black and crusted on outside top part of fungus and smooth, rust colored and/or greyish white underneath and orange/rust colored inside. These particular fungus look like half solid discs on the bark. Some of this clump of birch contains over-mature trees that have blown over and appear dead while lots of the clump contains younger trees and mature trees. Is the fungus still good if it’s attached to the blown over trees from this clump of birch? I would love to send pics, just to be sure the fungus is chaga. Thanks
I found a 4 pound chaga with the White cap on the bottom it had some white starting to infuse the inside, My guess is this is mold from being a old one, is the rest of it still good, sorry I cut it up throughout the night and white and I am drying it only real as of what’s left.
I just harvested chaga that is marbled gold and black, on the inside. Is this common?
Reblogged this on Howlingfire's Blog and commented:
I just harvested some chaga….