Phaeophyscia orbicularis
Mealy Shadow is a soft gray-green foliose lichen recognized by its powdered lobes and shadowed apothecial discs. Mealy Shadow is one of Minnesota’s most widespread bark lichens, often appearing as a quiet, neutral-toned companion beside brighter species such as Candelaria concolor and Xanthoria parietina.
For identification details and comparison with other similar species, see the Phaeophyscia orbicularis in the Field Notes section.
A mature colony of Phaeophyscia orbicularis spreads across the bark of northern red oak, forming a pale gray, irregular rosette densely studded with brown apothecia. The lobes are uneven and slightly uplifted, with subtle granular texture on the surface consistent with sparse laminal soredia. Beneath, the thallus shows a brown lower cortex with brown rhizines anchoring it to the textured oak bark. This common hardwood species often forms expansive patches in well-lit woodland settings.
Mealy Shadow on Northern Red Oak
Broad gray rosette crowded with brown apothecia
Camera: Canon EOS 5D Mk IV
Lens: EF100mm f/2.8L Macro IS USM
Settings: ISO 200 • Aperture f/13 • Shutter 0.4 s
E21A9242-45 • Size: 4744x3163
A mature colony of Phaeophyscia orbicularis forms a gray, foliose rosette on the bark of northern red oak. Numerous brown apothecia are scattered across the lobes, while sparse laminal soredia appear as pale granular patches on the upper surface. The thallus is loosely attached with abundant rhizines beneath, anchoring it to the textured oak bark. Bright yellow patches of Candelaria concolor surround the colony, illustrating a typical nitrogen-tolerant hardwood bark community in Minnesota woodlands.
Phaeophyscia orbicularis on Northern Red Oak
Apotheciate rosette with sparse laminal soredia
Camera: Canon EOS 5D Mk IV
Lens: EF100mm f/2.8L Macro IS USM
Settings: ISO 200 • Aperture f/16 • Shutter 1/200 s
E21A9136 • Size: 2685x4028
Mealy Shadow Lichen
A matte gray thallus with mealy margins blending into the bark’s coarse texture.
Camera: Canon EOS 5D Mk IV
Lens: EF100mm f/2.8L Macro IS USM
Settings: ISO 200 • Aperture f/9.0 • Shutter 2.5 s
E21A8055 Size: 6720×4480
The colony forms dense, rounded patches of narrow lobes dusted with pale soredia. Dark-centered apothecia, when present, give the species its characteristic “shadowed” appearance.
E21A8057 Candleflame in the Company of Shadows