1270 CARDUACEAE 
41. Helianthus tracheliifolius Willd. Perennial, deep green. Stems 7-20 dm. tall, 
pubescent, but commonly only roughened by the remains of the hair-bases in age : leaves 
mainly opposite ; blades lanceolate to oblong-lanceolate, 8-18 cm. long, acuminate, sharply 
serrate, or with the teeth obscured by the revolute margins, scabrous above, more or less 
pubescent beneath, narrowed into petiole-like bases : headsshowy : involucral bracts linear- 
lanceolate to lanceolate, with slenderly elongated lax tips, pubescent and finely ciliate : 
ray-flowers 9-19 ; ligules yellow, 3-4 cm. long: disk about 1.5 cm. wide. 
In dry soil, Pennsylvania to Wisconsin, North Carolina and Arkansas. 
42. Helianthus hirsütus Raf. Perennial, hirsute or hispid. Stems 5-12 dm. tall, 
sometimes branching: leaves opposite; blades usually firm, lanceolate, 5-15 cm. long, 
acuminate, serrate or nearly entire: heads showy: involucral bracts linear-lanceolate, lan- 
ceolate or oblong-lanceolate, each attenuate into long spreading tips, hispidulous: ray- 
flowers 12-15 ; ligules 2.5-3.5 cm. long: disk 1.5-2 cm. broad. 
In dry soil, Pennsylvania to Wisconsin, Georgia and Texas. 
43. Helianthus divaricàtus L.  Perennial, deep green. Stems 3-12 dm. tall, simple 
or with slender branches above, commonly smooth, and glabrous, sometimes glaucescent: 
leaves opposite, spreading; blades lanceolate or ovate-lanceolate, acuminate, entire or 
sharply and coarsely serrate, sessile or nearly so: heads rather showy: involucral bracts 
lanceolate or oblong-lanceolate, 8-10 mm. long, acuminate, ciliate: ray-flowers 7-15 ; lig- 
ules 2-2.5 cm. long: disk 1-1.5 em. broad. 
In dry, open woods, Ontario to the Northwest Territory to Florida and Louisiana. Summer. 
44. Helianthus móllis Lam.  Perennial, canescent. Stems 6-10 dm. tall, often 
branched above: leaves opposite; blades ovate to ovate-lanceolate, 5-15 cm. long, acute 
or acuminate, nearly entire or serrate, sessile or clasping : heads showy: involucral bracts 
oblong-lanceolate to lanceolate, or cuneate with a lanceolate tip, 1-1.5 em. long, acuminate, 
bristly, the outer ones spreading: ray-flowers 13-26; ligules yellow, 2-3 cm. long: disk 
2-3 cm. broad. 
In dry often barren grounds, New York to Iowa, Georgia and Texas. Summer. 
97. ENCELIA Adans. 
Annual or perennial herbs or shrubby plants, with usually pubescent or glandular foli- 
age. Leavesalternate or opposite : blades mainly of an ovate type. Heads radiate or rarely 
discoid, often showy, peduncled. Involucres hemispheric or flattish : bracts mainly lanceo- 
late or linear-lanceolate. Receptacle somewhat convex, chaffy. Ray-flowers several, neu- 
tral: ligules yellow. Disk-flowers perfect, fruit-producing : corollas yellow or brown. 
Anthers slightly sagittate at the base. Stigmas with elongated pubescent appendages. 
Achenes flattened. Pappus wanting, or a small awn at each margin of the achene. The 
plants flower from spring to fall. 
Achenes pilose, ciliate above: pappus of 2 short awns. 1. E. subaristata. 
Achenes glabrous: pappus wanting. 2. E. calva. 
1l. Encelia subaristàta A. Gray. Foliage hispidulous and somewhat canescent. 
Stems 3-11 dm. tall, branching: leaves opposite; blades ovate to hastate, 3-7 cm. long, 
crenate-serrate, subcordate at the base : peduncles elongated : heads solitary, rather showy : 
involucral bracts linear-lanceolate to lanceolate : ray-flowers 13-19 ; ligules yellow, 8-10 
mm. long: achenes 5-6 mm. long, pilose, ciliate near the top, with 2 rigid hispidulous 
awns 3 as long as the achene or shorter. 
On plains and prairies, Texas and adjacent Mexico. 
2. Encelia cálva (Engelm. & Gray) A. Gray. Foliage scabrous to hispidulous. 
Stems 3-9 dm. tall, branching: leaves opposite; blades deltoid-ovate to hastate, 2-7 cm. 
long, serrate, broadly cuneate or subcordate at the base : peduncles elongated : heads soli- 
tary, showy : involucral bracts linear-lanceolate to almost linear, the outer with spreading 
tips, densely hispidulous: ray-flowers 11-17 ; ligules 10-12 mm. long: achenes 5-6 mm. 
long, glabrous, without pappus. 
On stony hills, Texas and adjacent Mexico. 
98. HELIANTHÉLLA T. &G. 
Perennial caulescent herbs with tuber-bearing roots. Leaves alternate or opposite : 
blades entire or sparingly toothed. Heads radiate, heterogamous, showy, peduncled. In- 
volucres often hemispheric : bracts imbricated in 2 or 3 series, the outer often longer than 
the inner. Ray-flowers neutral: ligules yellow. Disk-flowers perfect, fruit-producing : 
