FLORA OF THE PACIFIC COAST 



area is entirely omitted since its flora is described 

 in a succeeding chapter. 



Coastal Formations (chiefly of the Upper Sonoran 

 zone) . Except for those places where the bluffs or 

 mountains extend to the water's edge, the shore line 

 exhibits a series of sandy beaches often backed by 

 a belt of dunes of varying width. Here is found 

 a characteristic xerophytic vegetation composed 

 chiefly of perennial herbs and shrubs. Since the 

 floral composition is fairly uniform from north to 

 south one may study these plants equally well near 

 almost any of the beach resorts. 



Very characteristic of the dunes are the Abronias, 

 or sand verbenas, of which A. umbellata (rose-pink) 

 and A. latifolia (yellow) are the most common. The 

 roots of these plants are often much enlarged, thus 

 serving for storage, while the broad opposite leaves 

 are thick and succulent. The most marked examples 

 of succulent herbage, however, are the Mesembryan- 

 themums, or sea figs, the enlarged often trigonous 

 leaves of which serve admirably as water reservoirs. 

 The pale scurfy-leaved saltbushes (Atriplex) and 

 the hairy-coated Franserias (F. bipinnatifida and F. 

 chamissonis), bear unmistakable evidence of their 

 xerophytic nature. More beautiful than the humble 

 herbs just mentioned are the bush lupines of the 

 dunes with their attractive racemes of yellow, 

 bluish, or purplish flowers and silvery-pubescent 

 compound leaves. Similarly pleasing are the Oeno- 

 theras, the most common of which is OE. cheiranthi- 

 folia, whose tough woody stems either trail over the 

 dunes or arise reluctantly from them and bear, in 

 addition to their hairy-protected leaves, an almost 

 continuous succession of yellow blossoms. On the 

 southern beaches occur "Calandrinia maritima, a 

 succulent glabrous annual with red flowers, and 

 Amblyopappus pnsillus, an erect fleshy Composite 

 herb found also on the coasts of Chile. The sand 

 strawberry (Fragaria chilensis), another species 

 which occurs also in Chile, will be found from San 

 Luis Obispo to Vancouver. The dune tansy 

 (Tanacetum camphoratum) is restricted to the 

 beaches and dunes from Monterey to Humboldt, but 

 is replaced on the coast of Oregon and Washington 

 by T. huronense. From Monterey northward will be 

 found the beach pea ( 'Lathy rus littoralis) which 

 although botanically a sweet pea, looks much more 

 like a Hosackia or a lupine because of its silky- 

 villous herbage. 



Flora of the Plains and Lower Foothill Slopes 

 (Lower Sonoran and Upper Sonoran zones). In 

 early springtime, when the sun's warm rays heat up 



148 



