THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 2OI 



12. PARHELIA FLAVICANS Tuck. 



Parmelia perlata flavicans Tuck. Lich. Calif. 13. 1866. 

 Parmelia flavicans Tuck. Syn. N. Am. Lich. I: 53. 1882. 

 Parmelia flavicans Herre, Proc. Wash. Acad. Sci. 7: 352. 1906. 



Thallus large, orbicular, becoming very large and irregular; 

 surface smooth, or centrally more or less wrinkled and plicate; 

 often isidiose-sorediate; lobes long, sinuous, imbricate, marginally 

 crenate and undulate, their tips thin and rounded; color of thallus 

 pale yellow or more often a yellowish green; beneath black with 

 chestnut margin; smooth or wrinkled; generally naked, but also 

 more or less interruptedly black fibrillose; thallus and medulla not 

 affected by KOH; medulla blood-red with CaCl 2 O 2 , fading to pale 

 pink. 



Apothecia not uncommon; disk chestnut in dried specimens; in 

 the field sometimes of same color as thallus; margin entire or crenu- 

 late, often sorediate; spores ovoid or ellipsoid, often falsely bilocu- 



7 . S I2 

 lar, L ^- - fi. 



1122 



Common on rocks in the foothills; a well marked species, not to 

 be confused with any other. Distribution not known; I have ex- 

 amined specimens collected by Baker and Nutting in northeastern 

 California, in either Modoc or Lassen County, and now in the 

 University of California herbarium. Probably occurring every- 

 where west of the Sierra Nevada watershed. 



13. PARMELIA CAPERATA (L.)Ach. 



Lichen caperatus Linne, Sp. Plant. 2: 1147. 1753. 



Parmelia caperata Ach. Meth. Lich. 216. 1803. 



Parmelia caperata Tuck. Syn. N. Am. Lich. I. 63. 1882, (in part). 



Parmelia caperata Herre, Proc. W. Acad. Sci. 7: 357. 1906. 



Thallus large, orbiculate to indeterminate, with smooth but 

 wrinkled and plicate surface; marginally much dissected; lobes long, 

 imbricate, laciniate, their margins often pointed, elevated and rough- 

 ened, their tips rounded, becoming isidiose centrally or sprinkled 

 with concolorous soredia; color pale yellowish or greenish; beneath 

 black with narrow brown margin; more or less abundantly clothed 

 with short black fibrils; cortex and medulla yellow with KOH; 

 CaCl 2 O 2 -. 



