If you've been studying medicinal mushrooms much in recent years, you've likely heard about Chaga (Inonotus obliquus). Chaga is peculiar among medicinal mushrooms in that the part that is gathered for medicine isn't technically a mushroom (i.e., not a spore-bearing fruiting body of a fungus) but rather a sclerotial mass. For years, I hadn't thought much about this distinction, that is until I came upon the above tree late last month.
I immediately recognized the char-like growths on this dead-standing Birch (Betula sp.) tree, but was puzzled by the unfamiliar sight beneath the bark. Could this be a Chaga fruiting body? A little research turned up an article by Maine mushroom forager and author Greg Marley called Chaga; The Elusive Fruiting Body of Inonotus obliquus (Chaga) which confirmed my hunch. In the article (which includes photographs), Marley describes discovering a tree with a similar fruiting body during a November 2014 foray with the Maine Mycological Association.
I should mention that, photographs aside, I didn't gather medicine from this tree. It's my understanding that Chaga sclerotium is best gathered for medicine while the host tree is still alive. I've included photos below in hopes that they'll serve as search images for you, in case you've yet to meet this fungus in the flesh. Don't expect to find chunks of Chaga lined up on a log or sitting on a shelf of Birch Polypore, as shown in the last photos; I arranged those scenes for your enjoyment.
For more search images and info on Inonotus obliquus, see David Spahr's article. For a discussion on Chaga conservation, see the two videos by Arthur Haines. (To view the following images in full-size, click here.)