Have you seen these in your garden? Lichens are not a plant, but rather somewhere between algae and fungus. The growth of lichens is often a good indicator of good air quality and contributes to soil formation! We have many large lichens on the grounds of our headquarters at River Farm in Alexandria, VA, and we appreciate all they do to contribute to the health of our ecosystem. #AHSGardening #AmericanHorticulturalSociety #Lichen #RiverFarmVA