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CLASS ASCOMYCETEAE 



Apothecia with thalloid exciple. Rinodina 



Three more genera present in the U.S. 

 Apothecia with thalloid exciple. (See also Caloplaca and Rinodina, 

 above.) 

 Thallus foliose or rarely somewhat fruticose. 



Thallus more or less yellow in color, ascospores hyaline. 



Family Teloschistaceae 

 One genus in the U.S., foliose or some species a little fruticose. 



Teloschistes 

 Thallus greenish gray to ashy or darker, ascospores brown. 



Family Physciaceae 

 Upper cortex plectenchymatous. 



Exciple colored like the thallus. Physcia 



Exciple becoming black. Pyxine 



Upper cortex not plectenchymatous. Anaptychia 



Thallus definitely foliose, sometimes also slightly fruticose. 

 Spores nonseptate, hyaline. Family Parmeliaceae 



Thallus yellow, spores 16 to 32 in each ascus. 



Candelaria 

 Thallus rarely yellow, spores 8 in each ascus. 



Thallus flat, apothecia not marginal. Parrnelia 



Thallus more or less upright, apothecia marginal. 



Cetraria 

 (Besides the foregoing only one other small genus in the 

 U.S.) 

 Spores septate. 



One genus in the U.S. 

 Thallus plainly fruticose or pendent. 

 Ascospores nonseptate. 

 Thallus dorsiventral. 

 Thallus upright or pendent. 

 Greenish gray or straw-colored. 

 Brownish to brown. 

 Ascospores 1 to 3 septate. 

 Thallus crustose to squamulose. 

 Spores minute, many in each ascus. 



Apothecia with thalloid exciple, immersed. Acarospora 

 Apothecium with proper exciple, immersed to sessile. 



Biatorella 

 Two other small genera in the U.S. 

 Ascospores usually 8 or less in each ascus. Here may also be 

 sought some genera in Families Caloplacaceae and Buel- 

 liaceae (see above). 

 Ascospores large, with thick wall. 



Single genus in the U.S. 

 Ascospores with thin wall. 

 Ascospores nf)nseptate, small. 

 Ascospores 1 to 3 septate. Thallus crustose. 



Lecania 

 Ascospores transversely and longitudinally septate. 



Phlydis 

 (About six other small genera in the U.S.) 



1 



Family Stictaceae 



Sticta 

 Family Usneaceae 



Evernia 



Usnea 



Alectoria 



Ranialina 



Family Acarosporaceae 



Family Pertusariaceae 

 Pertusaria 



Family Lecanoraceae 

 Lecanora 



