How to identify: Usnea


Close-up of Usnea lichenUsnea is very sensitive to air pollution and so is normally only found growing in clean air environments.

Some species of Usnea are more sensitive to air pollutants than others. Can you find this lichen growing near you?


  • Generally grows hanging from tree branches
  • Thread like, resembling a grey beard

Common names
Old Man's Beard, Beard Lichen, or Treemoss.


Did you know?

Cartoon scientist

  • Usnea has been used in medicine for at least 1,000 years. Usnic acid, found in most species, has strong antibiotic and antifungal properties
  • This lichen is actually edible and high in vitamin C. Though we don't recommend trying it!