Black tree lichen (also called bear hair lichen) is an epiphyte--growing on tree branches and bark, depending on the trees for support and access to light but not parasitic in any way. The tangled brown to black lichen filaments hang from the branches, resembling clumps of hair that might have been snagged as a bear walked by. Sometimes the lichen strands are nearly a yard long!
Early Euroamerican explorers and ethnographers mention that this lichen was an emergency food for the Plateau peoples including the Nez Perce. For the Nez Perce, this was also a regular part of their diet.