Strand and Dune Flora of the Pacific Coast 143 



cause the habitat is narrowly circumscribed and very definite. 

 Only native species are considered. Two important plants native 

 elsewhere have recently become established. Cal{ile edentula 

 (Bigel.) Hook, has appeared spontaneously, is widely distrib- 

 uted, and behaves like a native. A map giving its present dis- 

 tribution is provided (fig. 6b). Ammophila arenaria (L.) Link, 

 planted as a sand-binder in many places, promises to make itself 

 thoroughly at home. 



The flora of the stable dunes is much less definite, and selec- 

 tion of a representative list is consequently more difficult. Within 

 the glaciated region there are scarcely any areas of stabilized 

 sand. In Washington and Oregon, such areas are occupied by 

 shrubs and forest trees having no relation to stricdy maritime 

 conditions. 



In central and southern California there is a definite com- 

 munity which occupies dune surfaces as fast as sand movement 

 comes to an end, and which is superseded by chaparral, the 

 climax. This community consists of several short-lived shrubs 

 as dominants and an extensive list of subordinate herbs. A large 

 part of these are strictly coastal, rarely straying from the dunes; 

 others, although most characteristically dune species, also occur 

 to some extent in other environments and range inland for vary- 

 ing distances. These two classes are included in the present study. 

 A third group is made up of species not characteristically coastal, 

 but of considerable importance on stabilized sand. Prominent 

 among these are certain members of the "coastal sagebrush" 

 community of southern California, especially Eriogonum fas- 

 ciculatum Benth., Salvia mellifera Greene, and Artemisia cali- 

 fornica Less. Because of the common presence of these and their 

 similarity in ecologic make-up, this "dune shrub" community 

 may fairly be considered a minor unit within the coastal sage- 



