General:
Common Name: The Shadow Lichens. Alludes to the dark colour of the upper surface of most species. Small to medium stratified foliose lichens, corticate above and below, isidiate or sorediate or not, lobes closely appressed to semi-erect, elongate-linear to elongate (rarely short), averaging to 0.2–1.5 (–3) mm wide, thin. Upper surface usually brownish, K- (atranorin absent), dull, lacking pruina and white-spotting. Lower surface dark brown to black, occasionally pale, bearing scattered, short, simple rhizines. Medulla white (ours). Photobiont green.
Apothecia located over upper surface, averaging to 1–2.5 mm across, rim occasionally bearing short colourless hairs, disc dark; spores 2-celled, ellipsoid to spindle-shaped, brown, 8 per ascus.
Over rock, bark, moss and other substrates.
Notes: Of the 19 species of Phaeophyscia reported for North America, ten are known to occur in B.C. Phaeophyscia was formerly treated within Physcia.

Species description:
Lobes averaging to less than 1.5 mm wide; upper surface convex to rarely concave at lobe tips; rhizines projecting or not; distribution and status various AND
Thallus sorediate and/or isidiate (check lower surface of lobe margins); apothecia generally absent AND
Thallus isidiate (or apparently isidiate), isidia coarsely granular, often branchedcoralloid at maturity or, in extreme cases, lobulate; upper surface often dark brown AND
Lobes averaging to less than 0.8 mm wide; isidia never hairy; rhizines generally not distinctly protruding beyond lobe tips; usually over rock, occasionally over mossy rock AND
Lobes minute, averaging to less than 0.5 mm wide; lower surface pale; southern intermontane; rare

Reactions:
All spot tests negative

Contents:
No lichen substances reported.

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

Synonyms and Alternate Names:
Physcia nigricans (Flörke) Stizenb.