113 



Arenaria peploides, and the sea verbena, Glehnia littoralis, are 

 thrifty but less frequent in the same zone. The growth of all 

 these species serves to check the drifting sand. Thrifty planta- 

 tions of Ammophila now cover the exposed front of the foremost 

 dunes at Gearhart rendering them practically permanent. 



On the dune crests the prevailing vegetation consists of the 

 Ambrosia-like Franseria chamissonis; the sand verbena, Abronia 

 latifolia; the shrubby knotweed, Polygonum paronychia, and the 

 bear-berry, Arctostaphylos uva-ursa. Here also, less frequent 

 are found Lupinus littoralis, the strawberry, Fragaria chiliensis, 

 and the morning glory, Convolulus soldanella. Dune tansy, 

 Tanacetum camphor atum, and the strawberry become super- 

 abundant upon stabilized dunes at Gearhart immediately north 

 of the mouth of the Neconicum River. 



The forest upon and back of the dune ridge is a dense tangle 

 characterized by the dominance of lodgepole pine, Pinus con- 

 torta, and the prevalence of devil's club, Echinopanax horrida, 

 the hillman root, Echinocystis oreganus, the sallal, Gaultheria 

 shallon, the salmon berry, Rub us spectabilis, the stonecrop, 

 Sedum oregonum, and a rich growth of smaller plants including 

 mosses and ferns. 



Comment 



Similarity of topography is noted in the three areas under 

 consideration. Each is a narrow ridge of shore sands fronting 

 upon a great sea and having at its back a marshland indented 

 with water-channels and shallows. At Seaside and Seven-mile 

 Island the waters are salt and tidal. 



Common to all three areas are Cakile and Ammophila both 

 serving as sand-binders. The latter by means of its leaf clusters, 

 rootlets and branching rhizomes is most successful in checking 

 drifting sand and is extensively planted for that purpose along 

 the west coast. 



The perennial beach pea, Lathyrus maritimus, abundant 

 both at Seaside and Beach is replaced at Seven-mile Island by 

 the annual trailing-bean, Strophostyles ; however, the beach pea 

 is to be found on the coast sands of New Jersey somewhat far- 

 ther north, and is well-known as a beach plant along the shores 

 of all the Great Lakes and the northern coasts of both the Atlan- 

 tic and the Pacific. 



Trumpet creepers and grapevines form tangles and mats 



