<  Usnea scabrata
Usnea subfloridana  >
Click on Characteristic name for explanation. Click on image for larger version.
Usnea silesiaca

PNW Range:
  West sideOccasional
  East sideNone
  Immediate coastCommon
  Alpine or subalpineNone
Habitat: Common in oceanic areas from California to British Columbia, usually near the coast, sometimes in the Coast Ranges, sporadic in the Willamette-Puget trough.
Substrate: On conifers, hardwoods, and shrubs.
Synonymy: none
Usnea silesiaca - Field habit with Lobaria and Parmotrema
Field habit with Lobaria and Parmotrema
by B. McCune
Usnea silesiaca - Branches
by B. McCune
Usnea silesiaca - Branches
by B. McCune
Usnea silesiaca - Branches
by B. McCune
Usnea silesiaca - Branches
by B. McCune
Usnea silesiaca - Longitudinal section
Longitudinal section
by B. McCune
Usnea silesiaca - Base
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: Never
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: Almost always
Medulla P+ Yellow: Sometimes
Medulla K+ Orange or Red: Almost always
Medulla K+ Yellow: Rarely
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: Commonly
Soredia: Commonly
Lobules: Never

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