Usnic and other acids, found in many lichens, have antibacterial qualities and are still used in some antibiotic creams. Some lichens are used to create alcohol. Wolf lichen is a poison, used in Russia to poison wolves. Certain Native American tribes also used Wolf lichen to treat skin problems. Other lichens contain selenium, which is poisonous to livestock.
Litmus paper uses a lichen-derived dye.
Other lichens have been used for wool and silk dyes, making browns, yellows, reds and similar colors. Erosion Control or Acceleration Lichens that live on rocks often secrete acids that cause the rock to disintegrate and create soil. Lichens living on sand cover it from the erosion-causing wind, binding the sand together. Recently, environmental scientists have begun using lichens to analyze polutants in the air. Lichens tend to absorb chemicals in the atmosphere.