I discovered something about myself recently: all my favorite non-edible fungi are purple. At the top of the list is the violet viscid cort that is commonly seen in September and October. But coming in at a close second is the violet-toothed polypore (Trichaptum biforme), a common shelf fungus that appears on dead and dying hardwoods. It can be found in all 50 states, and in eastern North America it is one of the most commonly encountered fungi. On a recent walk in Sudbury (where these photos were taken) they were practically everywhere I looked. As a common saprobic fungus, the violet-toothed polypore plays an important role in our forests as a decomposer of dead wood. 

Where there’s one, there are many; the violet-toothed polypore grows in dense, sometimes overlapping clusters. Individual shelves are typically 1 to 2 inches across. Although the fruiting body can persist long enough to be found through the winter, fading to tan or white as it ages, new growth is produced spring through fall. From above, the often-pale, banded pattern is loosely reminiscent of a turkey tail fungus, with a lilac-colored margin. But the view from below tells a different story. The underside of a violet-toothed polypore is a violet, bumpy texture, which gives this fungus its name (e.g., the spore bearing surface is comprised of angular, almost tooth-like structures). Many of the T. biforme clusters I saw on this walk, however, were a strikingly bright purple, both above and below – presumably because they had only newly emerged. 

The next time you head out on a walk, take a look at dead standing tree trunks and fallen logs to see if you can spot a violet-toothed polypore for yourself.