Pitted Cetraria Lichen
The Pitted Cetraria, Cetraria lacunosa, Ach.Habitat.-On trees and old fence-rails, easily detached.
Vegetative organ (thaltus).-Leaf-like (foliaceous) the lobes rounded, the surface pitted (lacunose); pearl to slate colour above, white to darker below, margins scalloped.
Fruiting disks (apothecia).-Abundant on the lobes, somewhat elevated, the disk light chestnut, growing darker, the margin entire.
Name.-The specific name lacunosa is from the Latin lacus, a saucer, referring to the pitted surface of the thallus.