Lichen

From Usenet Archives:

Evernia

The plant is edible (Sturtevant). A thick tea is used on running sores (Murphey).

 

Letharia, Wolf Lichen

This bright yellow tree lichen contains a highly toxic acid. It was once combined with animal fat and nails and used in Europe to kill wolves (Vitt). It is also used as a dye plant.

 

Usnea, Old Man's Beard

The lichen is boiled for use as a dye (Gilmore). It is used medicinally as an antibiotic (Klein). (Usnea is a light grey color. Use the "rubberband" test for positive identification: break the stems and inside you will find a white, rubbery core that stretches a little like a rubberband.)

By Tom Elpel