358 HERRE 



13. PARMELIA SOREDICA Nylander. 



Thallus coriaceous, large to very large, orbicular, becoming 

 irregular, undulate, radiately plicate, closely adherent to the 

 substratum ; lobes rounded, complicate, imbricate, their mar- 

 gins ascendant and confluently white sorediate, except on pe- 

 riphery where they are dilated, smooth or wrinkled, with crenate 

 edges. Surface of lobes more or less sorediate ; central por- 

 tion of thallus finall}^ passing into sorediate heaps which be- 

 come detatched and fall away, leaving the outer portions to con- 

 tinue their growth ; color green to yellowish green ; beneath 

 black, with brown margin ; outer lobes sometimes with a few 

 white or dark fibrils. Apothecia abundant on large specimens ; 

 generally of small or medium size ; disk chestnut ; margin en- 

 tire or lobulate, usually sorediate. 



On trees, fences, roofs, and occasional on rocks. 



Common everywhere in the valleys and foothills and extend- 

 ing to the summit of the range ; especially conspicuous and well 

 grown on ^lercns lobata, on whose rough bark it seems to at- 

 tain its maximum development. 



Dr. Zahlbruckner writes: *' a P. conspe7'sa distat thallo 

 sorediis absito, reactionibus aliis, sporis microribus." 

 Parmclia soredica Nylander, Flora 68: 605. 1885. 



14. PARMELIA CONSPERSA (Ehrh.) Acharius. 



Thallus dilated, membranaceous, usualh^ 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 portion wrinkled or roughened, becoming isidiose, 

 thickened or elevated, 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. Apothecia 

 numerous ; margin incurved, crenate ; disk chestnut. 



Common on rocks throughout our range. 



Like Parmclia perforata this species often turns a beautiful 

 red or rose-purple color when pressed while wet,, and occasionally 

 one sees similarly discolored specimens on the rocks. 



