PARHELIA. 53 



1. P. perlata (L.) Ach.; thallus at length much dilated, 

 membranaceous, smooth, greenish-glaucesceut ; beneath black 

 with brown margins, rather obsoletely black-flbrillose, or largely 

 naked and very smooth; lobes ample, a little ascending, rounded, 

 the undulate margins not ciliate, but often white- sorediate; 

 apothecia (infrequent) ample to large ; disk chestnut ; margin 



entire. Spores ellipsoid, ^^ mic. Ach. L. U. p. 459. ' Fr. L. 



E.p. 59. Tuck. Lich. exs. n. 15. Nyl. Syn. 1, p. 379. 



Rocks, especially in the mountains of the northern States ; 

 and also on trunks ; Halsey View, 1823. Lake Superior, Agassiz. 



](&). P. flavicans, Tuckerm. herb. ; thallus ample, with the 

 texture of the last, pale-yellow, mostly naked beneath; lobes 

 sinuately lobulate, more or less sorediiferous, with naked edges; 

 apothecia ample, much as in the last. Spores also similar, but 

 ^^ mic. P. perlata, v. flavicans, Lich. Calif, p. 13. 



Rocks, coast of California, Bolander. No reactions with 

 chloride of lime or potash, observed. 



l(c). P. latissima, Fee; very much dilated, smooth, whitish- 

 glaucescent, for the most part wholly glabrous and shining 

 beneath; lobes rounded, the wavy margins naked, or now sore- 

 diiferous ; apothecia, in West Indian and South American spec- 

 imens, much as in P. perlata, but the spores much larger, reaching 



^j mic. Fee Suppl. p. 119. P. perlaia, v. latissima, Mont. 



Cuba, p. 231. Nyl. Syn. I, p. 379. P. glaberrima, Krempelh. in 

 Flora, 1869, p. 223. 



Trees ; tropical America ; but found also, though only as yet 

 infertile, in Texas, Lindheimer; Florida, Chapman; and South 

 Carolina, Eavenel. 



2. P. perforata (Jacq.) Ach. ; thallus at length much dilated, 

 coriaceous-rnembranaceous, smooth, glaucescent ; beneath brown- 

 ish-black, strongly but interruptedly black-fibrillose ; the rounded 

 lobes soon creuate, and cut, ciliate; apothecia (abundant) 

 ample to very large, commonly perforate, cyathiform; disk 



Chestnut ; margin entire. Spores ellipsoid, ^^ mic. Ach. L. 



U. p. 459. Fr. L. E. p. 58. Tuck. Lich. exs. n. 69. Nyl. Syn. 

 1, p. 377. Lobaria sub-mar ginalis, Michx. FL, flde Mull. 



* hypotropa, Nyl. ; more or less largely pale or even white 



beneath ; the lobes finally divided as in b, often sorediiferous. 



Syn.! I, p. 378. 



