THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 203 



This lichen probably ranges over western North America from 

 the sub-arctic region to northern Mexico, but is only positively re- 

 corded from the Saskatchewan, British America, by Nylander, and 

 from California by myself. An examination of the Tuckerman 

 Herb, shows that Bolander's No. 20, being the specimen on the upper 

 right hand corner of the sheet containing Tuckerman's material of 

 Parmelia caperata, is undoubtedly Parmelia soredica. This is the 

 specimen described by Tuckerman in his Synopsis, Pt. I, top of 

 page 64, 1882. 



15. PARMELIA CONSPERSA (Ehrh.) Ach. 



Lichen conspersus Ehrh. in Ach. Lich. Suec. Prodr. 118. 1798. 

 Parmelia conspersa Ach. Meth. Lich. 205. 1803. 

 Parmelia cons per s a Tuck. Syn.N. Am. Lich. I: 64. 1882. 

 Parmelia conspersa Herre, Proc. Wash. Acad. Sci. 7: 358. 1906. 



Thallus dilated, membranaceous, usually orbicular, but finally 

 irregular and greatly expanded ; marginally closely appressed, smooth, 

 often polished, much and intricately divided or lobed; the lobes 

 usually narrowed, often complicate and intricate; the central por- 

 tion wrinkled and roughened, becoming isidiose, thickened or eleva- 

 ted, finally forming irregular heaps detached from the substratum; 

 color varying from pale to dark yellowish or gray-green; beneath 

 pale to dark brown, or occasionally black, with short, scattered, 

 concolorous fibrils, or even merely tuberculate; marginally darker, 

 often lustrous; thallus and medulla yellow with KOH, the medulla 

 then changing to orange or red; neither affected by CaCl 2 02. 



Apothecia numerous; margin incurved, crenate; disk chestnut; 



4.9 6.5 

 spores short ellipsoid, -g /<. 



Common on rocks throughout our range. 



Like Parmelia perforata this species often turns a beautiful red 

 or rose-purple when pressed while wet, and occasionally one sees 

 similarly discolored specimens on the rocks. 



A lichen of world-wide distribution. 



1 6. PARMELIA PHYSODES (L.) Ach. 



Lichen physodes Linne, Sp. Plant. 2 : 1144. 1753. 

 Parmelia physodes Ach. Meth. Lich. 250. 1803. 



Proc. Wash. Acad. Sci., May, 1910. 



