Genus 66. THISTLE FAMILY. 481 
g. Helianthus laevigatus T. & G. Smooth 
Sunflower. Fig. 4460. 
Helianthus laevigatus T. & G. Fl. N. A. 2: 330. 1842. 
_ Stems slender, from a perennial root, simple or 
little branched, glabrous, or somewhat glaucous, 
2°-6° high. Leaves nearly all opposite, firm, gla- 
brous, lanceolate, short-petioled, or the upper sessile, 
serrulate or entire, pale beneath, acuminate, nar- 
nowed at the base, 3-6’ long, 4’-13’ wide, the mar- 
gins sometimes roughish-ciliate; heads few or soli- 
tary, 1’-13’ broad; involucre campanulate, its bracts 
lanceolate or ovate-lanceolate, firm, ciliolate, the 
tips of the outer ones spreading; rays 5-10; disk 
yellow; chaff linear; achenes slightly pubescent at 
the summit; pappus of 2 lanceolate or ovate owns, 
with or without 2 intermediate scales. 
In dry soil, mountains of Virginia, West Virginia 
and North Carolina. Aug.—Oct. 
to. Helianthus microcéphalus T. & G. 
Small Wood Sunflower. Fig. 4470. 
Helian hus parviflorus Bernh.; Spreng. Syst. 3: 617. 
1826. Not H.B.K. 1820. 
HY, microcephalus T. & G. Fl, N. A. 2: 329. 1842. 
Stems slender, glabrous, branched above, or 
rarely simple, 3°-6° high. Leaves thin or thin- 
nish, petioled, most of them opposite, lanceolate, 
or the lower ovate-lanceolate, rough above, canes- 
cent or puberulent beneath, long-acuminate at the 
apex, narrowed at the base, serrulate, or the 
lower serrate, 3-7’ long, 3’-13’ wide; heads com- 
monly several or numerous, I-14 wide, borne 
on slender, sometimes roughish peduncles; invo- 
lucre campanulate, 4-5” broad, its bracts lanceo- 
late or ovate, acute or acuminate, ciliolate, the 
tips of the outer ones spreading; chaff of the 
receptacle oblong, entire, or 3-toothed; rays 5-10; 
disk yellow; achenes nearly glabrous; pappus . 
_ usually of 2 subulate awns. 
In moist woods and along streams, Pennsylvania to 
ecorete west to Ohio, Missouri and Louisiana. July- 
ept. 
11. Helianthus gigantéus L. Tall, Giant or 
Wild Sunflower. Fig. 4471. 
Helianthus giganteus L. Sp. Pl. 905. 1753. 
Perennial by fleshy roots and creeping rootstocks; 
stems hispid or scabrous, at least above, branched near 
the summit, or simple, 3°-12° high. Leaves sessile or 
short-petioled, firm, lanceolate, very rough above, 
rough-pubescent beneath, serrate or denticulate, acumi- 
nate at the apex, narrowed at the base, many or all of 
the upper ones alternate but sometimes all opposite, 
2’-6’ long, 4#’-1’ wide; heads usually several, mostly 
long-peduncled, 134’-23" broad; involucre. hemispheric, 
its bracts squarrose, lanceolate-subulate, hirsute or 
ciliate, commonly as long as the diameter of the yel- 
lowish disk; chaff of the receptacle oblong-linear, 
acute; achenes oblong, glabrous; rays 10-20; pappus 
of 2 subulate awns. 
In swamps and wet meadows, Maine and Ontario to Sas- 
katchewan, Florida, Louisiana and Colorado. Stem com- 
monly purple. Aug.—Oct. 
Helianthus ambiguus (A. Gray) Britton, differing in 
having all but the uppermost leaves opposite and rounded 
at the base, found on Long Island, New York, and recorded : 
from Georgia, appears to be a hybrid, with this species one of its parents. 
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