— 6i — 



Parmelia stygia (L.) Ach. The dark brown, almost black, of the 

 thallus of this species is a distinguishing mark. It is smooth and shining, 

 the lobes are linear, many cleft and contorted, with curved tips. Beneath 

 it is black, with fine fibrils. The apothecia are not common, the disk is very 

 dark chestnut, with granulate margin. This species is found on rocks in 

 the higher mountains of the Eastern States. It is very abundant in Alaska. 



Fig. 6. (Reduced !^.) P. conspcrsa. 



Parmelia conspersa (Ehrh.) Ach. 

 (Fig. 6.) Thallus divided into slender 

 lobes which are smooth and polished. 

 At the centre are sometimes found 

 greenish soredia, but more fre- 

 quently apothecia are present; these 

 vary in size, are sometimes very 

 large. The disk is dark chestnut 

 with entire margin when young, 

 which becomes wavy and broken 

 with age. Beneath, the thallus is 

 usually very dark, with fine fibrils 

 here and there. Found on rocks 

 and stones in great abundance, and 

 usually fertile. It clings closely to 



the substratum, but when moist can be detached. 



Parmelia CAi'EUArA 

 (L.) Ach. (Fig. 7.) This 

 is one of our most con- 

 spicuous lichens. The 

 thallus is leaf-like, grow- 

 ing naturally in round 

 mats. It is a light pea 

 green, undulate, wrink- 

 led, usually covered, es- 

 pecially near the centre, 

 with soredia which are a 

 lighter green than the 

 thallus. The lobes are 

 rounded with entire tips. 

 Beneath it is black ex- 

 cept at the margin, where 

 Fig. 7. P. caperata. it is reddish brown; has 



some black fibrils. Apothecia are rare, when present they are cup shaped 

 with crenulate margins, which are often covered willi isidioid granules. 

 P. caperata is found on trees and rocks. 



