What do lichens look like?
• Lichens can be crustose: crust-like, stuck too tightly to the surface (rock, concrete, bark) to remove—these are not dye plants!
• Lichens can be foliose: leaf-like, having a distinct upper surface and a lower surface.
• Lichens can be fruticose: like little bushes or hair.
Yellow and orange crustose lichens. These are not used for dyeing.