Plant Guide > Mosses and Lichens > Lichens > Genus Parmelia

Genus Parmelia

Genus PARMELIA, (Ach.) De. Not.

Parmelias usually grow as horizontal mats, gray, blue-green, dark brown, or brown tinged with green. They are closely attached by black rhizoids to rocks and trees and are distinctly branched and lobed. If the thallus is torn across and viewed with a hand lens, the torn edge shows that the thallus is composed of a layer of long, loose, white fibres (the medullary layer) between thin but more substantial surface tissues (cortical layers).

Over the surface of the mat are scattered flat or saucer-shaped disks (apothecia) generally brown with a thin margin. These are numerous toward the centre. The apothecia have suggested the generic name Parmelia from parma, a small round shield. Many species have also a powdery appearance due to the bursting of the surface to emit little bodies (soredia) which may grow into lichens.

Parmelia Conspersa Lichen
Parmelia Perlata Lichen
Parmelia Physodes Lichen
Parmelia Saxatilis Lichen
Wrinkled Parmelia Lichen