General:
Common Name: The Mouse Lichens. Reflects the minute size and dull greyish brown colour of the species.
Minute to small stratified squamulose lichens (ours), corticate above, noncorticate below, isidiate (in BC), squamules closely appressed, subrotund to elongate, averaging to 0.5–1 mm wide (in BC), thin. Upper surface greyish brown, smooth. Lower surface pale, resting on dark hypothallus. Medulla white. Photobiont bluegreen.
Apothecia unknown in B.C. material.
Over trees and mossy rock.
Notes: Of the nine species of Parmeliella reported for North America, only one is known to occur in B.C. Parmeliella is closely related to Pannaria and differs primarily in the character of the apothecial rim, which is non-thalline (i.e., coloured differently from the upper surface) in the former genus and thalline in the latter. The taxonomic value of this distinction, however, is questionable. For points of distinction with similar lichens, see the descriptions under Pannaria.

Reactions:
All spot tests negative, except hymenium I+ strong blue.

Contents:
No lichen substances present (P.M. Jørgensen, Bergen, pers. comm., 1993).

Source:  Lichens of British Columbia

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration By:  Trevor Goward