]<)07] Hall. Compositae of Southern California. 41 



short : pappus-bristles 8 to 10, capillary, not dilated at base, cadu- 

 cous. Vallecito, northern Lower California, Orcutt, ace. to Gray. 

 Both of these species to be expected in San Diego Co. 



8. ACAMPTOPAPPUS Gray. 



Low round-topped desert shrubs with slender rigid stems and 

 entire alternate leaves. Heads spherical, 12 to 36-flowered, dis- 

 coid or radiate. Involucral bracts closely imbricated in about 3 

 series, very broad and obtuse, pale, the margins thin-scarious and 

 erose-fimbriate. Tube of disk-corollas funnelform; the lobes 

 lanceolate, acute. Style-tips thick, subulate. Achenes short- 

 turbinate, densely villous. Pappus of about 30 to 40 silvery awns, 

 some of them flattened especially above and equalling the corolla, 

 others setiform and shorter, all persistent. 



1. A. sphaerocephalus Gray, Proc. Am. Acad. viii. 634 

 (1873). Haplopappus sphaerocephalus Gray, PL Fendl. 76 

 (1849) ; Torr., Pacif. R. Kept. vii. pt.3, 12, t.vi. (1856). 



Herbage pale and glabrous or nearly so, the stems striate: 

 leaves linear or linear-spatulate, acute, .5 to 2 cm. long, some- 

 times fascicled: heads solitary terminating the branches, or in 

 loose terminal clusters : involucre 6 to 8 mm. high, its bracts com- 

 monly with a faint greenish subapical spot : rays none. 



An exceedingly interesting plant, by no means rare in the 

 Larrea and Yucca belts of the Desert Area (San Felipe, Chucka- 

 walla, Palm Cafion, Antelope Valley, Owens Valley, etc.), ex- 

 tending eastward to Arizona and Utah. 



A. SHOCKLEYI Gray, the only other species, occurs in south- 

 western Nevada (Shockley, ace. to Gray) and in the Inyo Mts.. 

 California (Austin, no. 501). It is easily distinguished by its 

 simpler monocephalous branches and larger heads with conspic- 

 uous yellow rays. 



9. HETEROTHECA Cass. 



Tall hairy herbs with alternate toothed leaves and radiate 

 heads of yellow flowers in a terminal cymose panicle. Involucre 

 hemispheric or broadly campanulate, its narrow bracts closely 

 imbricated in many series. Both ray and disk-flowers numerous 

 and fertile. Ray-achenes triangular-compressed with flat sides 



