The quest for the fruiting body of Inonotus obliquus.

Other names
= Boletus obliquus Ach. ex Pers.
= Fomes obliquus (Ach. ex Pers.) Cooke
= Fuscoporia obliqua (Ach. ex Pers.) Aoshima
= Mucronoporus obliqua (Ach. ex Pers.) Ellis & Everh. 1889
= Mucronoporus obliquua (Ach. ex Pers.) Ellis & Everh.
= Phaeoporus obliquus (Ach. ex Pers.) J. Schröt.
= Phellinus obliquus (Ach. ex Pers.) Pat.
= Physisporus obliquus (Ach. ex Pers.) Chevall.
= Polyporus obliquus (Ach. ex Pers.) Fr.
= Poria obliqua (Ach. ex Pers.) P. Karst. 1881

It appears that very few people ever saw the fruiting body of Inonotus obliquus.  I get the impression that no one who is alive did!  Those who claim they did, did not have a camera to take a good picture.  Many people have a misconception as to what it is. 
1. Many sources consider Chaga, or the Clinker Polypore, the fruiting body.
2.  "Inonotus obliquus is an extract of Chaga mushrooms"
3. On this site :
they show some kind of growth on a tree and misidentify it as Inonotus obliquus fruiting body.

Here are some statements made on the web site Mushroom Observer:

By: Darvin DeShazer (darv)
Summary: Photos - hard to find
Ryvarden has a line drawing from collection 23546, of the basidia and hymenium in Polyporaaceae s.l., Vol 10 of Fungi Europaei. So maybe he has finally seen one, or at least dried. 
There is one small photo of the fruiting body in Vol II of the Swiss series by Breitenbach & Kranzlin.
Online photo:
Bernicchia, Annarosa. 2005. Polyporaceae s.l. Fungi Europaei Vol. 10. Edizioni Candusso, Alassio, Italy. 806p.
Breitenbach J. and F. Kranzlin. 1986. Fungi of Switzerland Vol. 2. Mykologia, Luzern. 412p.

By: Tom Volk (TomVolk)
Summary: Anyone ever seen the fruiting body?
Despite extensive searches, I’ve never seen the fruiting body. Hal Burdsall has never seen it. Leif Ryvarden (of Gilbertson and Ryvarden) has never seen it. Has anyone ever actually seen the fruiting body?

The online photo (link given above) is not convincing and does not look like the fruiting body as described in mushroom guides.  As an example, Gary H. Lincoff gives this description, on page 467:
"fertile portion up to 5 mm thick, crustlike, thin, dark brown.  Tubes: 5-10 mm long; oblique, usually split in front.  Pores 3-5 per mm, angular to elongated; whitish, becoming dark brown."
No size of the fruiting body is given, only its thickness.  This leads to an impression that it can be any size.  In this picture, on Mushroom observer, the photographer shows what they believe is the fruiting body:
This is what they saw after removing 3 feet of bark.  A close-up should have been taken to show the pores and tubes.  I have seen similar brown under the bark in birch infected with Inonotus obliquus.  I think this is another indicator of Inonotus obliquus infection, but not the true fruiting body.  The Russians call the birch Clinker Polypore a Chaga.  I think this is better name for it than Clinker Polypore or even Inonotus obliquus.  Since it is not a fruiting body nor a polypore.  Guides usually show a fruiting body of a particular specie of fungus but in this case they show a  Chaga since there is no picture of the fruiting body available.  It is time to find one and get a good picture.

The quest begins!
First day 8/1/08.
Day 2, 8/3/08
Day 3, 8/13/08
Day 4, 8/18/08
Day 5, 9/12/08 - BINGO!!
Revisited 9/25/08

Revisited 4/15/11
History of confirmation.
11/27/08 Old fruiting body on Black Birch