I think this was an ornamental cherry tree, going by what is on the city's tree database, though they may have removed this tree from the list; the roots look ok for that ID. So the trunk/roots would have been Prunus avium. There are two or tree different mushrooms here. I didn't measure them, but the main crop seemed to reach around 8 or 9 cm in diameter.
Hi Wendy, I’m on a cell phone right now so I’m not seeing the photos at the larger size… But so far the first ones appear to be Armillaria sp. One of the honey mushrooms. The second one looks like a Ganoderma, an artist conk Or similar … but I’m not absolutely sure because there are polypores that grow to that size, and that colouring at the base of trees.
Thanks, @Frog. To my very untrained eye, the first one looks a lot like the Armillaria unidentifed at Armillaria (unidentified). I didn't even know the term "honey mushroom". Wikipedia's article is interesting, particularly the section on edibility, and particularly the bit about not having alcohol within twelve/24 hours of ingesting it. Oh, and also the bit about their forming the largest living fungi in the world. From Armillaria - Wikipedia: I see now that two years ago I posted a similar one for a friend at https://forums.botanicalgarden.ubc.ca/threads/fungi-flat-brown-centres-white-gills.103815/, also from the base of an ornamental cherry. I'm sorry, I didn't remember a thing about it. It was easy to find when I had a name to query; I didn't think it would be reasonable to check every fungi forum posting for a photo that looked similar.
