THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 195 



ened, convolute, more or less ascending; margins of inner lobes 

 covered with confluent, concolorous soredia; under surface black, 

 wrinkled, papillose, margin brownish; from strongly and densely 

 black fibrillose to smooth. KOH yellow; CaCl 2 2 - . 



Sterile. On old fences and roofs along the seashore, and occa- 

 sionally on trees and rocks. Not found outside the maritime region. 

 A cosmopolitan lichen. 



2. PARMELIA PERFORATA (Wulf.) Ach. 



Lichen perforatus Wulfen in Jacquin Coll. 1 : 116, pi. j. 1786. 

 Parmelia perforata Ach. Meth. Lich. 217* 1803. 

 Parmelia perforata Tuck. Syn. N. Am. Lien. I: 53. 1882. 

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



Thallus large, finally greatly dilated, smooth, gray, tinged with 

 greenish, or whitish; the ample lobes crenate, becoming marginally 

 much dissected; margins of inner lobes often confluently gray sore- 

 diate; lobes fringed (in f. ciliata Nyl.) with long, black, simple or 

 branched cilia; under side black, with a broad chestnut margin; 

 interruptedly clothed with dense patches of black fibrils; KOH yel- 

 low; the medulla white, becoming rose-red with KOH. 



Apothecia rare, medium to large; margin entire; disk chestnut, 



8 5 ii 

 rarely perforate; spores ellipsoid, ' __ g- /* 



On trees, mossy rocks, and earth. 



This large and handsome plant occurs throughout the Santa Cruz 

 mountains, usually sterile; on shaded, moss-covered sandstone cliffs 

 immense circular mats are formed; in many cases these coalesce into 

 great carpets covering many square feet. 



Fruiting specimens occur abundantly on Quercus and Umbellu- 

 laria, about the head of Alpine Creek Canon, at an altitude of 1000 

 feet, and fertile plants are occasional elsewhere. Nearly all the 

 apothecia seen here belie the specific name, being imperforate. 



Occurring generally throughout Europe and North America 

 (including the West Indies), and also in Australasia, Ceylon, Japan, 

 and the Isle of Mauritius. 



