Sunday, November 20, 2011

Eastern Speckled Shield Lichen

Eastern Speckled Shield Lichen - Punctelia bolliana
I arrived at this identification based on the following features:
  • bluish-grey thallus
  • growing on the bark of deciduous trees 
  • rather large brown apothecia (first picture below)
  • brown to black dots (pycnidia) on the thallus surface (see second picture below)
  • white, grainy spots (pseudocyphellae) on the thallus surface (see third picture below)
  • whitish to tan underside with pale rhizines
  • K + on the cortext (I got a greenish-yellow color)