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Usnea cornuta

PNW Range:
  West sideOccasional
  East sideNone
  Immediate coastCommon
  Alpine or subalpineNone
Habitat: Coastal forests, scrub, wetlands, and partly forested lawns.
Substrate: On both conifers and hardwoods.
Synonymy: none
Usnea cornuta - Habit
by B. McCune
Usnea cornuta - Soralia
by B. McCune
Usnea cornuta - Habit
by B. McCune
Scale: Bar=1mm unless noted
Growth Form
Fruticose: Almost always
Foliose: Never
Crustose: Never
Appressed Foliose: Never
Fluffy Foliose or Strappy: Never
Dangling Hair: Sometimes
Erect Hair: Commonly
Appressed Hair: Never
Stalks With Squamules: Never
Stalks: Sometimes
Squamules: Never
Single Holdfast: Almost always
Dangling Nets: Never

Upper Surface
Upper Surface Color    (Dry) 
   Pale Yellow Green: Almost always
   Pale Green: 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

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

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

Usnic Acid: Almost always
Cortex KC+ Yellow: Almost always
Medulla P+ Orange or Red: Commonly
Medulla P+ Yellow: Rarely
Medulla K+ Orange or Red: Commonly
Medulla K+ Yellow: Commonly
Sexual Reproduction
Perithecia: Never
Apothecia: Rarely
   Mazaedium: Never
Disk Color    (Dry) 
   Disk Pale Greenish: Almost always
   Disk Brown or Tan: Almost always

Asexual Reproduction
Isidia: Sometimes
Soredia: Sometimes
Lobules: Never

Usnea Specific
Papillae: Almost always
Branches Cigar Shaped: Almost always
Central Axis Pale Yellow: Never
Cortex Reddish in Part: Never
Central Axis Thick: Never
Main Branches Nearly Unbranched: Never
Branch Surface Wrinkled: Never
Fibrils Abundant: Commonly