Tephromela atra #

Taxon #

Tephromela atra

Organization #

Select Crustose Species

Identification #

A crustose species with striking contrast between the epruinose, shiny black apothecia which are set in a usually bright white rim which is concolorous with a bright white thallus. The apothecia usually grow larger than many other crustose species on rocks when fully mature which makes the apothecia that much more striking. Lacking soredia and isidia.

Substrate #

On rock in full sun, common in the alpine. Reported from more southern parts of its range on dust-impregnated wood (CLH) and with one report from trees (Thomson 1979 in Spribille et al. 2023). Any specimens found on wood or bark likely deserve more detailed examination.

Upper cortex K+ yellow, C-, KC- Pd- (CLH)

Medulla K-, C, KC-, Pd- (CLH)

Notes #

One of the few crustose species we included in our field guide due to its near ubiquity in Alaska and cosmopolitan distribution beyond. It is often encountered in the alpine or open situations below alpine.