Varicellaria rhodocarpa (Körber) Th. Fr.

Thallus white, pale grey or creamy whitish, granular or lumpy, or smooth in part, often with soredia in random heaps; apothecia sunken in the thallus or slightly raised, without a distinct rim, the disc surrounded by amorphous thalline material, often covered in masses of thalline medullary material; paraphyses forming a white spongy medulla visible macroscopically between the asci as seen from above; asci 250-450 × 90-150  µ, visible individually as pale brownish spots in the disc; spores 1 per ascus, 200-400 × 70-140  µ, with walls about 25  µ thick, with one septum that often breaks resulting in the separate dispersal of the two spore halves.

Reactions: Thallus C+ deep red (persistent), UV- or UV+ yellow.

Contents: Lecanoric acid and usually also lichexanthone.

Habitat: On conifer bark, less often wood, above the winter snowpack. All forested elevations.

Similar Species: Macroscopically, this species could be mistaken for Phlyctis, which has spores with numerous cells, and which has a C- thallus. Sorediate Ochrolechia species may appear similar, but the C reaction of these is usually fleeting, or pinkish, not lasting deep red.

Specimens: Björk 9848, 12283, 14300.

Local Status: Occasional.