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Usnea cavernosa

PNW Range:
  West sideUncommon
  East sideUncommon
  Immediate coastUncommon
  Alpine or subalpineNone
Habitat: Widespread, boreal, s in mountains to Arizona, California, and Mexico; uncommon and scattered in PNW.
Substrate: Usually on conifers.
Synonymy: none
Usnea cavernosa - Branches
by B. McCune
Usnea cavernosa - Branches
by B. McCune
Usnea cavernosa - Branches
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: Almost always
Erect Hair: Never
Appressed Hair: Never
Stalks With Squamules: Never
Stalks: Never
Squamules: Never
Single Holdfast: Sometimes
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: Commonly
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 K+ Orange or Red: Almost always
Medulla K+ Yellow: Sometimes
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: Never
Soredia: Never
Lobules: Never

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