—59- 



Fig. 2. P. tiliacea. 



Parmelia tiliacea (Hoffm.) Floerk. (Fig. 2.) 

 This pretty lichen grows on rocks, trees, and 

 dead wood; it adheres closely to the substratum. 

 The lobes are narrow and round, quite smooth. 

 Glaucescent in color usually, but sometimes a 

 light gray. Beneath it is black and densely 

 covered with black fibrils. Apothecia are fre- 

 quent, medium in size. The disk is dark brown 

 with a reddish tinge, the margin is crenulate. 

 Parmelia Borkeri Turn. While this is not an uncommon species it is 

 not so generally found as the variety rtaiecta. The thallus is very rough 

 and is often covered with white soredia which give it a speckled appearance. 

 It clings quite closely to the trees or dead wood on which it is found. Is 

 greenish brown in color, beneath is lighter, at the margins are white hair- 

 like fibrils. The apothecia are large with entire margins, the disk dark 

 chestnut. 



Parmelia Borreri Turn, var. rudecta, Tuckm. (Plate VI. i.) — In 

 general appearance the variety is much like P. Borreri, only it is thickly 

 covered with isidioid granules, the lobes are more divided and the margins 

 are often broken, showing the woolly medullary layer. It does not cling so 

 closely to the substratum. Underneath the thallus is light brown, and is 

 covered thickly with short, dark fibrils. Apothecia are not frequent. Is 

 found on trees, dead wood and rocks. 



Fig. 



sa.xatilis 



Parmelia saxatilis (L.) 

 Fr. (Fig. 3.) Thallus with 

 many cleft, narrow, blunt 

 lobes, more or less reticu- 

 lated and lacunose, margins 

 wavy with white soredia. 

 The color is greenish or 

 ashy gray, sometimes turn- 

 ing to reddish brown. Be- 

 neath it is black and well 

 covered with black fibrils. 

 The apothecia are medium 

 in size with rather an irreg. 

 ular margin, the disk is 

 chestnut. 



Parmelia sa.xatilis (L.) Fr. var. sllcata, Nyl. This variety is dis- 

 tinguished from P. saxatilis by the presence of conspicuous rounded or 

 oblong soredia, which become confluent, giving the surface of the thallus 1 

 mealy appearance. Beneath it is very black and covered with short stiff 

 black fibrils. Is found on dead wood and rocks with P . sa.xatilis. 



