164 W. S. Cooper 



four species of Tanacetum native to North America — the two 

 Pacific species, T. htironense Nutt., ranging from New Bruns- 

 wick and Maine to the Great Lakes and Hudson Bay, and T. 

 bipinnattim (L.) Schultz, occurring from the lower Mackenzie 

 River westward through central Alaska into eastern Siberia, and, 

 according to Fernald (1923), across northern Asia to Russian 

 Lapland. All four species are closely similar. Fernald suggests 

 that T. huronense may fairly be considered a variety of T. bipin- 

 natum. All but T. bipinnatum are rather strictly coastal, except 

 that T. huronense is also found on the shores of the Great Lakes. 



Species of Stable Dunes 



Dominants. — Eriogonum parvifolium Sm. (fig. 8^) is an im- 

 portant dominant in the dune shrub community throughout its 

 range, which extends from San Francisco to the Mexican bound- 

 ary. It sometimes strays inland a short distance, and occasionally 

 occurs in habitats other than dune sand, such as bluffs and ter- 

 races. The large genus Eriogonum is confined to western North 

 America, where its members are conspicuous features of the 

 vegetation in semiarid regions. The present species belongs to a 

 group composed mainly of shrubs. A close relative is E. fascicu- 

 latum Benth., one of the most important dominants of the coastal 

 sagebrush climax of southern California. * 



Lupinus arboreus Sims (fig. 8^) is not confined to dune sand. 

 It occurs in all sorts of sandy places, and is occasionally found at 

 considerable distances inland. It is hardly a typical member of 

 the dune shrub community. It ranges from Humboldt Bay 

 southward to Ensenada, Baja California. 



Lupinus chamissonis Eschsch. (fig. 8c) is one of the most 

 characteristic dominants in the dune shrub community. It is 

 common from Marin County to southern California. There is 



