278 coMPOsiT.E. (composite family.) 



§ 1. Annuals; leaves mostly alternate , petiolate ; receptacle flat ; disk brownish- 



1. H. annuus, L. (Common Suxflower.) Tall, rough ; leaves triple- 

 ribbed, ovate or the lower cordate, serrate ; involucral scales broadly ovate to 

 obloug, long-pointed, ciliate; disk usually 1' broad or more. — Minn, to Tex., 

 and westward ; long cultivated, and occasionally found iu waste grounds. 



2. H. petiolaris, Xutt. More slender, 1-3° high; leaves oblong- or 

 ovate-lanceolate, smaller (1 -3' long), mostly entire; scales lanceolate or ob- 

 long-lanceolate, seldom ciliate ; disk Y broad or more. — Minn, to Tex., and 

 westward. 



§ 2. Perennials ; receptacle convex or at length low-conical ; loicer leaves usualli) 



opposite. 



* Involucral scales loose, becoming sqxiarrose, narrowlij lanceolate, pointed (^' 



long) ; disk usualli/ purple or brownish ; leaves linear, l-nerved. 



3. H. orgy^lis, DC. Stem glabrous, tall, very leafy ; leaves mostly al- 

 ternate, linear to filiform and entire, or the lowest lanceolate and serrulate ; 

 scales filiform-attenuate. — Dry plains. Mo. to Neb., south and westward. 



4. H. angustifolius, L. Stem slender (2-6° high), usually scabrous; 

 leaves long and linear, sessile, entire, with revolute margins ; heads loosely 

 corymbed, long-peduncled ; scales acute or pointed. — Low pine barrens, N. J. 

 to Ky., and southward. 



* * Involucral scales closer, more imbricated, short, unequal and not foUaceous ; 



leaves lanceolate to ovate, mostly opposite and 3-nerved. 

 -t- Disk dark. 



5. H. atrorubens, L. Rough-hairy ; stem slender (2 -4° high), smooth 

 and naked and forking above ; leaves thinnish, ovate or oval to oblong-lanceolate, 

 or the lowest heart-shaped (3-6' long), serrate, abruptly contracted into a 

 margined petiole ; heads small, corymbed ; scales ovate, obtuse, ciliolate, ap- 

 pressed ; rays 10 - 16 ; pappus of 2 fringed scales. — Dry soil, Va. to Ark., and 

 southward. 



6. H. rigidus, Desf. Stem stout (2 - 6° high or more), simple or spar- 

 ingly branched, rough ; leaves very thick and rigid, rough both sides, oblong-lan- 

 ceolate, usually pointed at both ends, nearly sessile, entire or serrate, the lowest 

 oval ; heads nearly solitary, pretty large ; scales ovate or oblong, obtuse, or 

 mostly acute, ciliate, appressed ; rays 20 - 25 , pappus of 2 large and often sev- 

 eral small scales. — Dry prairies, Mich, to 111., and westward. 



-t- -1- Disk yellow. 



7. H. Isetiflorus, Pers. Closely resembling the last; leaves rathet 

 thinner; heads single or corymbed; scales rather fewer (in 2 or 3 rows), nar 

 rower and acute or mostly acuminate. — Dry open places, Ohio to Wise, and 

 Minn., and southward. — Rays showy, 1-2' long. 



8. H. OCCidentalis, Riddell. Somewhat hairy, stem slender, simple, 

 naked above (1-3° high, sending out runners from the base), bearing 1-5 

 small heads on long peduncles ; lowest leaves oval or lanceolate-ovate, entire or 

 obscurely serrate, roughish-pubescent beneath, abruptly contracted into long hairy 

 petioles ; the upper small and remote ; scales ovate to lanceolate, acute or pointed, 

 sometimes ciliate. — Dry barrens, Ohio to Wise, and Minn., and southward. 



