THELOSCHISTES. 49 



less yellow ; the narrow-linear, dichotomously divided branches 

 smooth, or now puberulent, and terminating, for the most part, 

 in fibrillose-ramulose tips ; apothecia scattered ; disk orange ; 



margin often radiately fibrillose. Spores ellipsoid, ^ mic. 



Parmelia, Eschw. in Mart. Fl. Bras. p. 223. Pliyscia, Tucker m. 

 Obs. Lich. I c. 4, p. 384. 



"a. erectish, much compressed, rather sparingly divided, the 

 many-cleft tips ciliate-fibrillose ; from glaucescent-whitish with 

 yellow fibrils becoming yellow throughout above, when the under 

 side continues often whitish ; smooth ; apothecia sub-terminal, 



middling-sized to largish, commonly radiate. Parmelia chrys- 



ophthalma, Ach. Metli. p. 267. Tuck. Lich. exs. n. 80. Pliyscia, 

 Nyl. Syn. I, p. 410 (v.pubera & Capensi excl.). 



b. flavicans, Wallr. ; spreading, and becoming elongated and 

 pendulous; teretish, or compressed-terete, and now somewhat 

 channelled ; divaricately much-branched ; yellow, or now whit- 

 ening; smooth, or often puberulent; apothecia smallish, scat- 

 tered, the marginal fibres mostly deficient. Evernia flavicans, 



Fr.L.E.p.28. Physcia. Nyl. Syn.\,p.4QQ. Borrera flavi- 

 cans, Capensis, & pubera, Ach. L. U. p. 502. 



Trees. a. Northern and middle States (MiMenberg), 



Jacq. Coll. 1786. Minnesota, I. A. Lapham. Louisiana, Hale. 

 Texas, Wright. Kocky Mountains, Hall California, Bolander. 

 b. Southern States, fertile. South Carolina (Bosc), Mi- 

 chaux FL 1803, to Texas, Wright. California, Herb. Gray. 

 Mexico, Nylander. Occurring also, sterile and sorediiferous, 

 northward, along the coast. Nantucket, Tuckerman. And even 

 Newfoundland (Nyl.). This extended form (b) offers no satis- 

 factory differences to separate it from the other. Nor are its 

 puberulent conditions otherwise distinguishable from the smooth 

 ones. 



* * Thallus foliaceous, oppressed (rarely ascendant and at 

 length teretish), the cortical layer parenchymatous throughout. 



2. T. parietinus (L.) Norm. ; thallus foliaceous, membrana- 

 ceous, orbicular, from pale- at length bright-yellow, and orange ; 

 the appressed, radiant, crenate, often plaited lobes for the most 

 part dilated and rounded above ; apothecia middling-sized, 

 mostly orange, with an entire, at length flexuous border. Spores 

 ellipsoid, ^ mic. Parmelia, Fr. L. E. p. 72, a. Tuck. Lick. 



