PARMELIACEAE 81 



i. Algae Pleurococcus, Protococcus, Palmella or Cystococcus 



a. Asci many-spored ; apothecia cespitose on a one-leaved thallus 



Glypholecia 153 



b. Asci 1-32-spored 



(1) Thallus foliose, horizontal or upright, rarely fruticose, typically dor- 



siventral 



(a) Thallus with cyphellae or pseudocyphellae or furnished with well- 



developed clubshaped cephalodia 

 x. Lower side of thallus with cyphellae or pseudocyphellae 

 (x) Apothecia with thalline exciple 

 m. Spores 2-celled 



(m) Spores clear *Diphanosticta 189 



(n) Spores brown *Diphaeosticta 189 



n. Spores 4-many-celled 



(111) Spores clear *Phanosticta 189 



(n) Spores brown Sticta 188 



(y) Apothecia with proper exciple only 



*Dysticta 189 

 y. Lower side of thallus without cyphellae or pseudocyphellae ; thallus 

 typically with cephalodia 

 (x) Algae Protococcus Lobaria 185 



(y) Algae Cystococcus, i. e., in mucose colonies 



*Cystolobis 188 



(b) Thallus typically without cyphellae, pseudocyphellae, and cephalodia 



Subfamily Parmeliae 207 

 x. Asci 16-32-spored Candelaria 209 



y. Asci 2-8-spored 



(x) Cortex on both sides of thallus 

 m. Apothecia superficial 



(m) Lower cortex more or less cellular, usually with rhizoids 



Parmelia 211 

 (incl. Parmeliopsis 209) 

 (n) Lower cortex without rhizoids, spongy, of net-like hyphae 



Anzia 213 

 n. Apothecia marginal or terminal ; thallus often fruticose 

 (m) Disks upright from the beginning 



Cetraria 214 

 (n) Disks on the under side of thallus lobes, later upright by 

 the twisting of the lobes 



Nephromopsis 216 

 (y) Cortex on the upper side alone 

 m. Apothecia superficial ; lower surface without cyphellae 



Physcidia 209 

 n. Apothecial terminal ; cyphellae on lower side 



Heterodea 208 



(2) Thallus fruticose, erect or hanging, often long and hair-like ; radial, 



rarely dorsiventral in structure Subfamily Usneae 216 

 (a) Spores i-celled or unknown 



