130 University of California Publications in Botany. [VOL. 3 



achenes. Ray-flowers neutral. Achenes thick, slightly com- 

 pressed, 4-sided or elliptic in cross-section. Pappus of pointed 

 paleae borne at the angles of the achene, often with very small 

 intervening scales, all caducous. 



Annuals: receptacle flat or nearly so. 



Involucral bracts ovate, abruptly attenuate 1. H. annuus. 



Involucral bracts lanceolate, gradually attenuate. 



Foliage green: mountain species 2. H. petiolaris. 



Foliage white with a strigose pubescence: desert species 



3. H. tephrodes. 



Perennials: receptacle convex to low-conical. 



Outer bracts exceeding the disk, lanceolate or linear-subulate. 



Pappus-paleae slender-subulate 4. H. Parishii. 



Pappus-paleae broadly lanceolate 5. H. Calif 'ornicus. 



Outer bracts not exceeding disk, ovate, acute 6. H. gracilentus. 



1. H. annuus L., Sp. PL 904 (1753). (COMMON SUNFLOWER. 

 Erect and simple or more or less branching, 5 to 30 dm. high : 



herbage rough-hispid: leaves petiolate, deltoid-ovate, serrate, the 

 uppermost narrow and often entire : bracts of the involucre ovate, 

 slenderly acuminate, ciliate: bracts of the receptacle 3-cleft at 

 apex, the middle lobe lanceolate and longer than the others : rays 

 about 2 or 3 cm. long. 



Common along roadsides and in waste places throughout 

 western North America. 



2. H. petiolaris Nutt., Journ. Phila. Acad. ii. 115 (1821). 

 Slender plant with simple or branched stems, 3 to 9 dm. high : 



herbage scabrous to sparsely strigose-pubescent : leaves lanceo- 

 late, acute, entire or nearly so, the blades about 5 cm. long, nar- 

 rowed to the petiole or the lower with broad base : involucre 1 to 

 1.5 cm. high ; its bracts lanceolate-acuminate, merely scabrous or 

 obscurely ciliate, sometimes canescent at base but not villous : 

 bracts of the receptacle 3-cleft at apex; middle lobe lanceolate, 

 much longer than the others, somewhat hispid : rays about 2 cm. 

 long. 



Fredalba Park, in the Transition Zone of the San Bernardino 

 Mts., Miss Nora Pettibone, ace. to Parish; generally distributed 

 in western North America. 



