Anyway, I ran with the idea and came up with this tutorial on using bark + fauxtex (a homemade substitute for latex) to apply tree bark directly to your skin for a quick, easy, and super realistic camouflage makeup.
For this makeup you will need:
1 cup water
1/4 cup tapioca flour
1 packet of plain gelatin
Yellow, Green and Red food coloring to make a brown tint
1 tsp solid coconut oil (optional)
The above video shows how to apply the fauxtex and bark to your face (with Portuguese annotations).