PAHMELIA. 



197 



land districts, and on hills of minor elevation, as the Pent- 

 lands. We have only met with it occasionally in fructifica- 

 tion, however, in the woods on Kinnoull Hill, — so rare is it 

 in the fertile state. Its most frequent variety (vav.p/ii/sodes) 

 is the Parmelia physodes of older authors. Its spermogones 

 are the black points formerly mentioned as frequently stud- 

 ding the surface of the lacinise ; they are spherical, unicel- 

 lular, and have a dense, tough envelope. The spermatia are 

 linear and straight. This species is the " dark crottle" of 

 the Scottish peasantry, by whom it has been used to dye 

 woollen stuffs brown. It is one of the Lichens capable of 

 yielding a gum similar to gum-arabic, and it has been 

 recommended by some authors as an edible species. It 

 occurs likewise on the Himalayas and in various foreign 

 countries. 



9. Pahmelia saxatilis {saxum, a stone or rock). Thal- 

 lus whitish -glaucous or bronze-coloured, membranaceous, 

 reticulate-lacunose, frequently sorediiferous or furfuraceous, 

 below black-fibrillose ; lacinise siniiate-lacinulate, sometimes 

 blackish-ciliate ; lacinulse divaricate-angulose ; extremities 

 retuse. Apothecium chestnut-coloured, margin sometimes 

 at length crenate. The " Sten-laf " of Sweden and Norway. 



A very common Lichen, growing not only, as its name 



