478 



COMPOSITAE. 



VOL. III. 



Leaves very scabrous on both sides. 



Leaves elongated-lanceolate, conduplicate, pinnately-veined. 



Heads numerous; leaves mostly alternate. 12. H. M aximiliani. 



Heads only i or 2 ; leaves, all but the upper, opposite. 13. H. Dalyi. 



Leaves lanceolate to ovate-lanceolate, flat, 3-nerved. 14. H. subtuberosus. 



Stem glabrous; leaves sessile by a truncate base. 17. H. divaricatus. 



Stem glabrous ; leaves petioled. 



Leaves lanceolate, firm, canescent and pale beneath. 15. H. grosse-serratus. 



Leaves linear-lanceolate, thin, green on both sides. 16. H. Kellermani. 



2. Leaves prevailingly ovate, ovate-lanceolate, or oblong. 



a. Leaves sessile, or very nearly so. 



Stem glabrous ; leaves divaricate. 17. H. divaricatus. 



Stem hirsute or hispid ; leaves ascending. 



Leaves cordate-clasping at the base. 1 8. H. mollis. 



Leaves narrowed from below the middle. 19. H. doronicoides. 



b. Leaves manifestly petioled. 

 Stem puberulent or glabrous. 



Leaves membranous or thin, slender-petioled, sharply serrate. 20. H. decapetalus. 



Leaves firmer, shorter-petioled, less serrate or entire. 



Bracts of the involucre much longer than the disk. 21. H. tracheliifolius. 



Bracts of the involucre about equalling the disk. 22. H. strumosus. 



Stem hirsute, hispid, or scabrous. 



Leaves rounded or truncate at the base, short-petioled. 23. H. hirsutus. 



Leaves, at least the upper, narrowed at the base. 



Bracts of the involucre ovate-lanceolate, appressed. 24. H. lae iflorus. 



Bracts of the involucre lanceolate-acuminate, spreading. 



Leaves villous-pubescent beneath. 25. H. tomentosus. 



Leaves scabrous or puberulent beneath. 26. H. iuberosus. 



i. Helianthus annuus L. Common Sunflower. 

 Fig. 4461. 



Helianthus annuus L. Sp. PI. 904. 1753. 



Helianthus lenticularis Dougl. Bot. Reg. pi. 1265. 1829. 



Stem hispid or scabrous, stout, branched above, 3-6 

 high, or in cultivated races sometimes 15 high. Leaves 

 all but the lower alternate, broadly ovate, petioled, 

 3-nerved, dentate or denticulate, acute at the apex, 

 rough on both sides, sometimes pubescent beneath, the 

 lower cordate at the base, 3'-i2 x long; heads in the wild 

 plant 3'-6' broad; disk dark purple or brown, io"-2' 

 broad ; involucre depressed, its bracts ovate to ovate- 

 lanceolate, usually long-acuminate or aristate, hispid- 

 ciliate; chaff of the flat receptacle 3-cleft; achenes 

 obovate-oblong, appressed-pubescent, or nearly glabrous. 



On prairies, etc., Minnesota to North Dakota, Idaho, Mis- 

 souri, Texas and California. Recorded north to Saskatche- 

 wan. Much larger in cultivation ; an occasional escape in 

 the east. Gold. Golden. Larea-bell. Comb-flower. Its flowers 

 yield honey and a yellow dye ; its leaves fodder ; its seeds, 

 an oil and food ; and its stalks a textile fibre. July-Sept. 



2. Helianthus petiolaris Nutt. Prairie Sun- 

 flower. Fig. 4462. 



H. petiolaris Nutt. Journ. Acad. Phila. 2: 115. 1821. 

 H. aridus Rydb. Bull. Torr. Club 32: 127. 1905. 



Annual, similar to the preceding species, but smaller 

 and with smaller heads ; stem strigose-hispid or hir- 

 sute, i-3 high. Leaves all but the lowest alternate, 

 petioled, oblong, ovate, or ovate-lanceolate, rough on 

 both sides, usually paler beneath than above, sometimes 

 canescent beneath, i'-3' long, entire, or denticulate, ob- 

 tuse or acutish at the apex, mostly narrowed at the 

 base; heads iJ'-3' broad; disk brown, mostly less than 

 10" broad; involucre depressed-hemispheric, its bracts 

 lanceolate or oblong-lanceolate, densely canescent, some- 

 times hispid-ciliate, acute or short-acuminate ; achenes 

 villous-pubescent, at least when young. 



On dry prairies, Minnesota to Saskatchewan, Oregon, 

 Iowa, Missouri, Texas and California. Found rarely in 

 waste places farther east. Races differ in leaf-form, size 

 and pubescence. June-Sept. 



