This colony of Hairy curtain crust (Stereum hirsutum) was making an impressive display on a fallen tree I passed today.

These fungi often start out hugging the wood they’re growing on (the scientific description is resupinate, with the fertile surface adnate to the substrate), then form wavy edged brackets are they age.

The upper surface is hairy (hence the epithet hirsutum), and the lower surface smooth, with no obvious pores.