E-Flora BC: Electronic Atlas of the Flora of British Columbia

General:
Minute to occasionally small stratified squamulose lichens, corticate above, corticate or not below, lacking isidia and soredia, squamules attached to substrate by entire lower surface, or by central portions only, closely appressed to loosely appressed, subrotund to rotund, thin to thick, averaging to 0.4–3 mm wide. Upper surface greyish to reddish brown. Lower surface becoming blackish, lacking rhizines, though usually bearing hairlike rhizohyphae. Medulla white. Photobiont green. Ascocarp a perithecium, immersed in upper surface, appearing blackish from above; spores simple (but occasionally appearing 2-celled, owing to oil droplets), ellipsoid, colourless, 8 per ascus. Over moss and soil.

Notes: Of the 16 species of Catapyrenium reported for North America, only three are known to occur in B.C. The species listed here have until recently been included in Dermatocarpon. Chemistry is of no diagnostic value in this genus and has been omitted in the species accounts.

Species description:
Lobes pale or reddish brown; widespread; spores 1-celled/simple, colourless, never intermixed with algal cells AND Fruiting bodies (perithecia) appearing dot-like from above, immersed in upper surface; lobes attached over central portion of lower surface, appressed throughout or margins somewhat raised all around; thalli rarely overlapping AND Lobes pale greyish brown, attached by uniformly dark woolly hairs/rhizohyphae; spores 16–23 m long, aligned in the ascus in two rows (i.e., biseriate); restricted to subalpine and alpine localities AND Lobe margins at most coarsely lobulate; lower surface lacking a lower cortex, medullary hyphae grading downward into minute, rhizine-like hairs/rhizohyphae