﻿Howe: Genus Teloschistes in North America 581 



Observations: This species, distinguished by its slender, sub- 

 terete thallus, has a largely maritime distribution above the thirty- 

 second parallel. It shows a transitional development of growth 

 from the slender subpendulous plants growing in littoral localities 

 to the more robust, caespitose plants that back the coast and inter- 

 grade toward the species T. chrysophthalmus. It shows also an in- 

 teresting transitional coloration from the more virescent shades of 

 the northern examples to the bright yellow southern Gulf speci- 

 mens which approach or are identical with Cornicularia crocea Ach. 



ExsicCATi: Merrill, Lich. Exsicc. S9- 



Teloschistes chrysophthalmus (L.) Th. Fries 

 Lichen chrysophthalmus L. Mant. 311. 1771. 

 Theloschistes chrysophthalmus Th. Fries, Gen. Het. Recog. 51. 



1 861. 



Type; In the Linnean herbarium, Burlington House, London, 

 England. 



Type locality: "Cap. b. spei." 



Original description: "Foliaceus subimbricatus linearis 

 lacerus ciUatus; peltis elevatis radiatis fulvis." 



Figure: Wulf; Jacq. Coll. pi. 4,f'3- 

 1786. 



Diagnosis : Thallus erect, compressed, 

 apothecial margins ciliate. 



Description (typical) : Thallus caes- 

 pitose (alt. 2 cm.), subrigid, subterete, 

 compressed or angulate; yellow or pale 

 virescent; cortex glabrous, often puberu- 

 lent, lacunose-rugose, rarely reticulate; 

 branches dichotomous (maximum width 

 3 mm.), generally paler below, apices 

 multifid, fibrillose. Apothecia common, 

 subterminal, concave or convex, marginate or emarginate, margins 

 radiantly ciliate, disk yellow to vitelline (maximum diameter 5 

 mm.). Spores polari-bilocular 10-18 X 5-8 /x. 



Contingent phases : (a) Thallus cinereous, apothecial margins 

 eciliate (= Physcia exilis Michx. Fl. Amer. 2 : 327. 1803.).* 



* Type locality: " Carolinae." Original Description: " P. pusilla, sordide exalbida- 

 scutellis minutis, lateralibus, planius. 



