-85- 
Apices blunt polymorpha 
Apices acuminate v. emplecta 
Branches never longitudinally rugose 
Soredia powdery. pollinaria 
Soredia subpulvinate v. humilis 
Soraliate 
Apices simple KOH — -? . . farinacea 
Apices multifid-erose intermedia 
Apices multifid-digitate KOH+ ? . subfarinacea 
Never sorediate or soraliate 
Branches canaliculate 
Laciniae open-canaliculate 
Branches slender, apothecia spurred canaliculata Fr. 
Branches wide, apothecia terminal subfasligiata 
Laciniae connivo-canaliculats 
Papillate canalicularis 
Epapillate 
Slender linearis 
Robust alludens 
Branches never canaliculate 
Papillate 
Terete, torulose 
Spores ellipsoid Willeyi 
Spores fusiform Montagnei 
Compressed 
KOH — ?. complanata 
KOH+?. denticulata 
Epapillate 
Terete, torulose attenuata 
Compressed 
Calcareous 
Laciniae concolorous. calicaris 
Laciniae apices black cuspidata 
Coriaceous 
Spores ellipsoid 
Branches laciniate, apo- 
thecia scattered fastigiata 
Branches wide, apothecia 
lateral .v. subampliata 
Spores fusiform stenospora 
Thallus never erect (pendulous) 
Laciniae bifacial -compressed 
Spores generally over 20/j. long . .usnea 
Spores generally under 20p. long usneoidella 
Laciniae bifacial-terete 
Cortex striate 
KOH+ anceps 
KOH — subanceps 
Cortex estriate .per anceps 
