PARMELIA. 



189 



margins naked. Apothecium chestnut-coloured; margin 

 rugose. Thallus often attains a diameter of upwards of a 

 foot ; the lobes of old plants become transversely rugose. 

 (E. B. 293.) 



One of the largest and coarsest of British species, grow- 

 ing on the trunks and roots of trees and on rocks in various 

 parts of the Scotch Lowlands and Highlands, as in the 

 Breadalbane district, about Inverary, on the Pentland Hills, 

 and on Craigie Hill in the vicinity of Perth; but it is not 

 very common, especially in fructification. Its spores are 

 large, fusiform, bilocular or uniseptate, and pale lemon- 

 yellow, — the characters of those of the genus Sticta, The 

 occasional presence of cyphellse seems also to indicate that this 

 species more properly belongs to the genus Sticta, in which 

 it was placed by Fries, under the name of Sticta glomulifera, 

 a name more characteristic of its structure and affinities 

 than the one given it by Schserer. In its young state it 

 closely resembles a following species, P. Icete-virens, which 

 moreover possesses spores and spermogones having similar 

 characters. Its spermogones are abundant and easily recog- 

 nized, scattered over the thallus, external to the region occu- 

 pied by the apothecia, in the form of large mammiform tu- 

 bercles, whose apices are depressed and marked by a brownish 



