Lichen body layers are architecturally arranged so each partner protects the other

Evidence

In their shared architecture, the algal cells are embedded like green beads in fabric woven of fungal hyphae. If you sliced a cross section of the thallus it would be like a cake with four layers. The upper surface, the cortex, feels like the top of a mushroom, smooth and leathery. It is tightly woven of fungal filaments, or hyphae, to hold in moisture. The dusky brown coloration acts like a natural sunscreen that shields the algal layer, which lies just below, from intense sunlight. — Robin Wall Kimmerer, Braiding Sweetgrass, 993

Categorization

• XREF: connects to: Lichens are symbiotic composites of fungus and alga forming one new organism — Robin Wall Kimmerer, Braiding Sweetgrass: Indigenous Wisdom,…, 987