PARMELIACEAE 



131 



(r) Thallus fruticose, erect 

 (s) Thallus podetium-like; apo- 

 thecia unknown 

 (n) Thallus flattened, not hollow, 

 dorsiventral 



(b) Spores 2-celled 



(c) Spores muriform, dark, large; asci 



1-spored 

 b. Asci myriosporous; apothecia cespitose on a 

 one-leaved thallus 

 2. Thallus with Scytonema or Nostoc 



a. Thallus large-leaved, with cyphellae, pseudo- 



cyphellae, or cephalodia 



(1) Lower surface of thallus with cyphellae or 



pseudocyphellae 



(a) Apothecia with thalHne exciple 

 X. Spores hyaline 



y. Spores dark 

 (x) Spores 2-celled 

 (y) Spores x-celled 



(b) Apothecia with proper exciple only 



(2) Lower surface without cyphellae; cephalo- 



dia usually present 



(a) Apothecia with thalline exciple 



(b) Apothecia with proper exciple only 



b. Thallus scaly to small-leafy, sometimes 



crustose, rarely large-leafy, without cy- 

 phellae, etc. 



(1) Lower surface of thallus with distinct 



forked veins; spores hyaline, x-celled 



(2) Lower surface scarcely or not at all 



veined; spores 1-2-celled 



(a) Upper cortex well-developed, distinct 

 X. Upper cortex with hyphae perpendicu- 

 lar to it 



(x) Upper cortex hairy or pilose 

 (y) Upper cortex not hairy 

 m. Apothecia with thalline exciple 

 (m) Algae Nostoc 

 r. Spores 1-celled 



(r) Upper and lower cortex well- 

 developed 

 (s) Lower cortex lacking 

 s. Spores 2-celled; both cortexes 

 present 

 (n) Algae iScytonema; spores 2-celled 

 n. Apothecia with proper exciple only 

 (m) Spores 1-celled 

 (n) Spores x-celled 

 y. Upper cortex of horizontal hyphae 



(b) Upper cortex indistinct; algae occupy- 



ing nearly whole width of thallus 



Duf ourea 240 ; 32 



Endocena 247 



Evernia 239; 32 

 Ramalina 242; 32 



Oropogon 242 



Glypholecia 216 



Subfamily Stictinac 



Podostictina 186 



Stictina 186 

 Merostictina 186 

 Dystictina 186 



Phycodiscis 185 

 Lobarina 185 



Subfamily Pannariae 

 Hydrothyria 177 



Erioderma 181 



Pannaria 180; 32 

 Lepidogium 177 



Hueella 180 

 Massalongia 178 



Parmeliella 178 

 Placynthium 178 

 Coccocarpia 181 



LepidocoUema 177; 32 



