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This is a very common Physcia in these mountains, on both oak bark and less common on granite. Recognize by abundant apothecia and heavy coarse pruina.

Foliose lichen, on granite, fairly exposed, with Lecanora muralis.
THALLUS: light gray, coarsely white pruinose, K+y, white underneath with white simple rhizines
MEDULLA: white, K-
APOTHECIA: lecanorine, black, densely coarsely white pruinose, substipitate, to 2 mm wide, flat


at 30x
at 30x, showing K+y spot test

Proposed Names

87% (1)
Used references: Nash’s Sonoran Flora
Based on chemical features: Cortex K+ yellow, medulla K-.

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= Observer’s choice
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