1907] Hall.Compositae of Southern California. 257 



lower ones more or less runcinate : heads terminal : involucre 8 to 

 10 mm. high, usually of 5 principal bracts and 5-flowered: 

 achenes striate : pappus-bristles 15 to 25, white or sordid, plumose 

 throughout. 



A species of the Sierra Nevada Mts. and northward : reported 

 from the mouth of Mill Creek Canon, San Bernardino Mts., by 

 Parish, no. 4577; not seen by me. 



4. S. runcinata Nu-tt., Trans. Am. Philos. Soc. ser. 2, vii. 427 

 (1841). 



Stems woody at base, rigidly and intricately much branched, 

 the nearly leafless branches divaricate or slightly ascending, 

 forming rounded bushy plants 4 to 6 dm. high: herbage pale, 

 glabrous : lower leaves runcinate ; upper leaves linear-subulate. 

 5 cm. or less long, many reduced to scales : heads solitary, on short 

 peduncles scattered along the branches or terminating short 

 geniculate branchlets : involucre 8 to 10 mm. high, commonly of 5 

 principal bracts and as many or more short calyculate ones: 

 flowers 3 to 5 : achenes narrowly oblong, striate : pappus-bristles 

 12 to 25, sordid, plumose to near the base. 



Lower Sonoran Zone of the Mohave and Colorado deserts from 

 Antelope Valley, Palm Springs, and San Felipe east and north ; 

 also in Lower California; nowhere abundant. Nuttall's speci- 

 men came from "Big Sandy Creek, a rivulet of the Colorado." 

 Rafinesque's Ptiloria pauciflora, of the Great Plains and Rocky 

 Mts., is probably a different species. 



Mr. L. H. Henderson 67 has referred specimens from White- 

 water, San Bernardino Co., Parish, no. 3228, as represented in 

 the Gray Herbarium, to S. lygodesmoides M. E. Jones. The speci- 

 men in Herb. Parish under this number is easily referable to 

 S. runcinata and differs from the description of S. lygodesmoides 

 in its divaricate branches, in the involucre (8 mm. high) of 5 

 principal bracts, and in the pappus, which is plumose two-thirds 

 the way down. 



PTILORIA DIVARICATA Greene, Eryth. i. 224 (1893) is doubt- 

 fully distinct from 8. runcinata. In plants grown at Berkeley 

 from seed gathered by N. C. Wilson, presumably with the type 



67 Bull. Torr. Club xxvii. 349 (1900). 



