35© HERRE 



On trees. An inconspicuous lichen, apparently rare in the 

 valleys and lower foothills. A few scattering specimens were 

 found on Schinus molle (pepper tree), growing with Thelo- 

 schistes -polycarfus and with T. ramulosus. Specimens sub- 

 mitted to Dr. Zahlbruckner were all referable to the two latter 

 species, but unmistakable T. concolor was determined by Dr. 

 Hasse as well as by myself. 

 Lichen concolor Dicks. PL Cryt. Brit. 2 : 18, fl. p,y. 8. 1785- 



1801. 

 Thelosclnstes concoIo7'T\\ck. S}^. N. Am. Lich. i : 51. 1882. 



VII. Parmelia Acharius. 



Thallus foliaceous, appressed, expanded, often very large, 

 variously lobed or laciniate, usually imbricate ; the lower sur- 

 face usually black or dark brown, often brown-margined, gen- 

 erally more or less black fibrillose. Apothecia shield-like, 

 scattered, often sub-pedicellate ; the disk usually chestnut ; 

 spores small, simple, colorless, ellipsoid or ovoid. 



This genus contains the largest and most conspicuous folia- 

 ceous lichens of our flora, and is well represented both m num- 

 ber of species and of individuals. 

 Parmelia Ach. Meth. Lich. 153. 1803. 



KEY TO THE SPECIES. 



a. Thallus dark. 



b. Bright shining brown, to dull brown, nearly black. 



c. Soredia absent ; on trees and rocks 9. olivacea^ 2>S^' 



cc. Soredia present. 



d. Soredia small; thalkis dark, medium to large, on rocks. 



10. sorediata^ 35^' 

 dd. Soredia conspicuous, erumpent; thallus gray to brown; 



small; on rocks 11. conspurcata, 357. 



aa. Thallus some shade of green. 



e. Thallus inflated, loosely attached; whitish to bright green. 

 f. Without perforations in tinder siuface ; lobes usually with 



terminal soredia 7. physodes^ 354. 



ff. With perforations in under surface; lobes longer, more in- 

 flated, without terminal soredia 8. cfitcromorp/ia^ 355' 



ee. Thallus not inflated. 



^. Color pale, whitish or glaucous. 



