<  Xanthoria parietina
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Xanthoria polycarpa

Overview
PNW Range:
  West sideCommon
  East sideCommon
  Immediate coastCommon
  Alpine or subalpineRare
Habitat: In a wide range of habitats at low to middle elevations, but most common on hardwood twigs; also on sagebrush in steppe and in other dry open habitats.
Substrate: Bark and wood, rarely rock; mostly on hardwoods but occasionally on conifers, often where nutrient enriched.
Comments:
Synonymy: Polycauliona polycarpa
Xanthoria polycarpa - Habit
Habit
by B. McCune
1/5
Xanthoria polycarpa - K test
K test
by B. McCune
2/5
Xanthoria polycarpa - Lower
Lower
by B. McCune
3/5
Xanthoria polycarpa - Habit
Habit
by B. McCune
4/5
Xanthoria polycarpa - Lobes
Lobes
by B. McCune
5/5
Scale: Bar=1mm unless noted
Growth Form
Fruticose: Commonly
Foliose: Almost always
Crustose: Never
Appressed Foliose: Sometimes
Fluffy Foliose or Strappy: Sometimes
Dangling Hair: Never
Erect Hair: Never
Appressed Hair: Never
Stalks With Squamules: Never
Stalks: Never
Squamules: Never
Single Holdfast: Never
Dangling Nets: Never
Lobe Width (mm): 0.5 (± 0.25)

Upper Surface
Upper Surface Color    (Dry) 
   Pale Green: Rarely
   Dark Green: Rarely
   Orange: Almost always
   Yellow: Almost always
Upper Surface Tomentose: Never
Upper Surface Pruinose or Scabrid: Never
Upper Surface with Network of Ridges: Never
Upper Surface with Pseudocyphellae: Never
   Upper Surface with Holes into Cavity: Never
Cilia on Margins: Never
Lower Surface (Foliose)
Lower Surface Color    (Dry) 
   Orange: Almost always
   Yellow: Almost always
   Whitish: Almost always
Veined Below: Never
Rhizinate Below: Never
   Rhizines Squarrose: Never
Tomentose Below: Never
Cyphellae: Never
Pseudocyphellae Below: Never
Papillae Below: Never

Interior
Inside (Medulla) Yellow or Orange: Never
Central Cord: Never
Hollow Stalks or Hollow Lobes: Never
Gelatinous: Never

Photobiont
Green Algae Primary Photobiont: Almost always
Cyanobacteria Primary Photobiont: Never
Internal Cephalodia: Never
External Cephalodia: Never

Chemistry
Cortex K+ Purple or Red: Almost always
Sexual Reproduction
Perithecia: Never
Apothecia: Almost always
   Mazaedium: Never
Disk Color    (Dry) 
   Disk Orange: Almost always
   Disk Yellow: Rarely

Asexual Reproduction
Isidia: Never
Soredia: Never
Lobules: Never