156 HERRE 



2. LOB ARIA SCROBICULATA (Scop.) DC. 



Lichen scrobiculatus Scopoli, Flor. Carn. 2 : 384. 1760. 

 Sticta scrobiculata Ach. Lich. Univ. 453. 1810. 

 Sticta scrobiculata Tuck. Syn. N. Am. Lich. 1: 102. 1882. 

 Sticta scrobiculata Herre, Proc. Wash. Acad. Sci. 7: 369. 1906. 

 Lobaria scrobiculata DC. Fl. Fr. 2: 402. 1805. 



Thallus of medium size, rounded or sub-orbicular, leathery, short- 

 lobed; surface more or less pitted or wrinkled; thickly sprinkled with 

 gray soredia; lobes rounded, imbricate, but little incised, more or less 

 crenate; color of herbarium specimens dull yellowish green or gray; 

 in the field often a dark liver-green; beneath densely villous, buff 

 to dark brown or dingy black; more or less interspersed with naked 

 white or pale spots. 



Sterile. Apparently without apothecia in America, but occurring 

 fertile in Europe. 



Common on trees and rocks in the mountains above 1500 feet. 

 Also very abundant on a sandstone cliff in Pilarcitos Creek Canon, 

 two miles from the Pacific, at from 200 to 300 feet altitude. 



A common plant of the temperate and sub-arctic regions of both 

 hemispheres. 



XXXIX. Sticta Schreb. 



Sticta Schreber, in L. Gen. PI. ed. 8: 2 : 768. 1791. 



Thallus foliaceous, usually conspicuous, often more or less ascen- 

 dant, the upper surface often sorediose or isidiose; cortex of the 

 under surface more or less broken, the white medulla showing as 

 white specks or heaps, known as cyphellae; more or less covered 

 beneath by rhizoids, passing into a fleecy nap. 



Apothecia scattered or marginal, in some species apparently never 

 present; spores colorless to brown, long-ellipsoid, spindle or needle- 

 like, 2-8 locular. 



About 150 species, dwelling on bark, earth, and rocks, best devel- 

 oped in the moist tropics and warm temperate regions. 



KEY TO THE SPECIES. 



A. Apothecia abundant; thallus lacunose-reticulate, the ridges often 

 with confluent gray soredia i. anthraspis 



