.'J72 Proceedings Portland Society Natural History 



Equisetum arvense Ribes hirtellum 



Burner Acetosella Oenothera muricata 



Polygonum allocarpum PI ant ago major var. 



intermedia 



In a few instances, such as the Carrying Place on Swans 

 Island, a well developed upper beach is present. In this lo- 

 cality the vegetation is predominated by Elymus arenarius 

 var. villosus, and associated with it are Lathy rus maritimus, 

 Cakile edentula, Rumex pallidas. Convolvulus sepium var. 

 pubescens and Myrica carolincnsis. 



A characteristic feature associated with many of the sand 

 and gravel beaches is the presence of an extremely moist 

 area where the beach adjoins the upland. Such places are 

 practically miniature swamps and should properly be con- 

 sidered with the other lowland association-types. They 

 are, however, of such general occurrence in connection with 

 beaches as to warrant describing them at this time. Water 

 leaching down from above keeps these areas constantly sup- 

 plied with moisture. Where the substratum is sandy or 

 gravelly this water does not accumulate on the surface but 

 is readily absorbed, owing to the porous nature of the soil. 

 The vegetation in such places is extremely characteristic 

 (Figure 22), and consists of species also present in lowlands 

 away from the coast. Prominent forms which almost in- 

 variably occur are: 



Calamagrostis canadensis Thalictrum polygamum 



Carex crinita I mpatiens biflora 



Carex stipata Cicuta maculata 



Iris versicolor Heracleum lanatum 



Alnus crispa var. mollis Scutellaria galericulata 



Rumex crispus Mentha arvensis var. 

 Lathyrus palustris var. canadensis 



pilosus Cuscuta Gronovii 



Where the substratum consists of clay, or ledges are pres- 

 ent, drainage is impeded and water tends to collect in little 



