DUNE VEGETATION AT SAN FRANCISCO 201 



Carduaceae 



Cirsium occidentale (Nutt.) Jepson. 



A white cottony plant about 4 to 6 dm. tall. 

 * Achillea lanulosa Nutt., Yarrow. 



Common; generally 3 to 4 dm. tall. 

 *Tanacetum camphoratum Less., Dune Tansy. 



Common; 4 to 6 dm. tall. 

 Artemisia pycnocephala DC, Sand Sagebrush. 



Not common; about 6 dm. tall; sometimes forms large patches. 

 Eriophyllum staechadifolium Lag., Lizard Tail. 



Diffuse undershrub, 6 dm. tall. 

 *Anaphalis margaritacea (L.) B. & H., Pearly Everlasting. 



Occurs in large clumps; plants 4 to 6 dm. tall. 

 *Ericameria ericoides (Less.) Jepson. 



Heath-like plant, 4 to 8 dm. tall; forming compact growth. 

 Erigeron canadensis L., Fleabane. 



Introduced annual in well established soil. 

 *Baccharis pilularis DC, Chaparral Broom. 



On the dunes this is a low shrub 2 to 4 dm. tall. 



Cichoriaceae 



Agoseris apargioides (Less.) Greene, False Dandelion. 



Mostly 0.5 to 1.5 dm. tall. 

 Lactuca scariola L., Prickly Lettuce. 



Introduced annual, in well established soil. 



SUMMARY 



The sand dunes of San Francisco lie close to the Pacific Ocean 

 south of Golden Gate Park, extending about 5 km. north and 

 south and 2 to 4 km. east and west. The chief pioneer plants 

 of the dunes are Franseria chamissonis and Abronia latifolia. 

 Other important species are Salix lasiolepis, Fragaria chilcnsis, 

 Lupinus arboreus, Lupinus chamissonis, Echinocystis fabacea, 

 Oenothera cheiranthifolia, Achillea lanulosa, Tanacetum cam- 

 phoratum, Anaphalis margaritacea, Ericameria ericoides, Bac- 

 charis pilularis. The vegetation is described for exposed points, 

 protected areas, and low places; the effects of undermining and 

 burying are briefly considered; plant associations are mentioned; 

 there is presented a systematic list of 48 species of which 40 are 

 native and 8 introduced. The chief part of the dunes is entirely 

 unaffected by introduced plants. 



