Old Man’s Beard Lichen or Usnea

A Cure from the Forest?

Commonly known as Old Man’s Beard, Usnea is a genus of lichen we commonly see hanging from tree branches looking like a scruffy bit of someone’s beard.

This lichen is an infection fighter. Unlike most modern antibiotics which disrupt the structure of a cell, this lichen prevents the metabolism of gram positive bacteria such as Streptococcus, Staphylococcus, and Mycobacterium. However, in high concentrations, Usnea may have some toxicity and the National Toxicology Program is evaluating this.

Like many lichens, Usnea does best in high humidity and it is easily found locally on trees in the coastal zone. People often assume that because it is frequently found on the dead branches of trees that it is responsible for the deterioration of the tree, however, lichens do not negatively affect trees. Usnea is an opportunist in that it benefits from foliage die-back when its algal component can more readily access sunlight.

You can see many examples of Usnea and a wide variety of other lichens, each of which may harbor as-yet-undiscovered healthful compounds, at most Coastal Rivers preserves – but I recommend Seal Cove Shore Preserve.
 

Above: Usnea, or Old Man’s Beard viewed up close (left) and very, very close using an app called Cosy Magnifier (right).