336 Herre 



My largest specimens do not exceed three-fourths of an inch in 

 height. Two fruiting specimens were found in Austrian Gulch. 



It will probably be found beside all perennial streams in deep 

 and shady canons. 



Identification by Dr. Hasse. 

 JRamalina 7'igida Ach. Syn. Meth. Lich. 294. 1814. 

 Lichen rigidus Pers. in Ach. 1. c. as syn. 



II. Cetraria (Acharius) Fries. 



Thallus fruticose, or in most of our species expanded folia- 

 ceous, with lobes more or less ascendant, narrowed and elongate ; 

 medullary layer cottony ; color very variable, green, white, yel- 

 low, brown and black. Apothecia, except in number one, 

 darker and of a different color from that of the thallus ; termi- 

 nal or marginal ; spores simple, ellipsoid, colorless. 

 Cetraria Ach. Meth. Lich. 292. 1803 ; in part. Lich. Univ. 



96. 1810. 

 Diifotirea Ach, Lich. Univ. 103. 1810; in part. 

 Cornicularia Ach. Lich. Univ. 124. 1810 ; in part. 

 Cetraria Fries, Lich. Europ. Reform. 34. 1831. 



KEY TO THK SPECIES. 



a. Thallus black or greenish black i. califoniica^ 337- 



aa. Thallus variously colored. 

 b. Thallus nol green or pale. 



c. Thallus yellow 8. Juniperi/ia^ 340- 



cc. Thallus some shade of brown. 

 d. Apothecia abundant. 



e. Thallus greenish to dark brown ; lobes ascendant, crowded, 



finally narrowed 2. c//iar/s, ^^J. 



ee. Thallus dark brown; lobes broad, flat, but little ascen- 

 dant 3 . platypliylla^ 33S . 



dd. Always sterile; lobes with white sorediate edges, 



4. chloroplivlla^ 33S. 

 bb. Thallus green or pale. 

 f. Foliaceous; green, more or less black basally bencatii ; edges 



laciniate; surface sorediate 6. glauca, 339. 



ff. Fruticose; lobes long, narrow, ascendant or pendulous. 

 g. Apothecia abundant, terminal; lobes white beneath. 



5. lacunosa stcnopIiyUay 339. 



