Plant Guide > Mosses and Lichens > Lichens > Genus Thelochistes > Yellow Wall Lichen

Yellow Wall Lichen

The Yellow Wall-lichen, Thelochistes parietinus (L.) Norm.

Habit and habitat.-On trees and rocks usually near bodies of water.

Vegetative organs (thallus).-Leaf-like, pale yellow to orange above, white below; loosely appressed to the surface on which it grows, the margins sometimes ascendant, not gelatinous when moist.

Fruiting organs (apothecia).-The disk orange, the margin (thalline exciple) entire.

Spores.-Colourless, ellipsoid, polar-bilocular.

Name.-The specific name parietina, is from the Latin parie (t-) s, a wall, referring to its habit of growing on stone walls.