Hill: Penobscot Vegetation 363 



The vegetation on these rocky headlands varies in dif- 

 ferent places. Where there is but little soil and rock out- 

 crops or boulders are common, lichens may be abundant, 

 especially foliose and fruticose forms, such as the parmelias, 

 umbilicarias and cladonias. Grasses early make their ap- 

 pearance in such places, growing in crevices and pockets 

 among the rocks. In less rocky areas they may carpet the 

 whole headland. Conspicuous species are Festuca rubra. 

 Danthonia compressa, Agrostis hyemalis, and Poa pratcnsis 

 and associated with these such characteristic herbaceous 

 forms as : 



Arenaria lateriflora Veronica percgrina 



Cerastium arvcnse Euphrasia stricta 



Potcntilla argcntea Euphrasia purpurea var. 



Potent ilia penns/jlvanica Randii 

 Epilobium adenocaulon Gnapludium polijcephalum 

 Anagallis arvensis 



In the wetter depressions Carex Oederi var. pumila. Ca- 

 reer Goodenovii, J uncus brevicaudatus and Vaccinia m mac- 

 rocarpon are frequent. Eventually shrubs appear and the 

 whole area may take on the appearance of the crests of the 

 bluffs with sprawling mats of Juniper as horizontal'^ and 

 Empetrum and great clumps of Juniperus communis var. 

 depressa, Myrica carolinensis, Primus virginiana and Rosa 

 virginiana. Stunted spruces are occasional, and if the ex- 

 treme conditions were modified, a coniferous forest would 

 doubtless develop eventually. 



Perhaps the most striking feature about the vegetation of 

 the sea cliffs and headlands — and of the beaches and 

 brackish marshes, to be described later — is the presence of 

 many species of arctic and subarctic affinities. The ex- 

 treme exposure of these habitats, the constant drenching 

 with cold spray to which they are subjected and the fre- 

 quent presence of fogs combine to render conditions much 

 like those in boreal regions and afford a habitat where 

 northern species can exist. The occurrence of this sub- 



