What city is named after this red spot?
If you know that this is the Baton Rouge lichen, then your first thought was probably the city of Baton Rouge, Louisiana. Baton Rouge is French for "red stick." Looking at the history of that city, you then probably found that instead, the city got its name from a red colored cypress tree that served as a boundary marker between the the Houma and Bayou Goula tribal hunting grounds. At that point, the story gets a bit murky about what caused the red color of that cypress tree. Some sources say that it was due to blood, but blood quickly turns brown as it dries. Other sources claim that the red color was due to the Baton Rouge lichen, which grows especially well on cypress trees and often colors the entire trunk a bright red, which makes it likely that this lichen did give Baton Rouge its name.