GENUS 66. THISTLE FAMILY. 479 
3. Helianthus angustifolius L. Narrow-leaved 
or Swamp Sunflower. Fig. 4463. 
Helianthus angustifolius L. Sp. Pl. 906. 1753. 
Perennial by slender rootstocks ; stems branched above, 
or simple, slender, rough or roughish above, often hir- 
sutes below, 2°-7° high. Leaves firm, entire, sessile, 
linear, slightly scabrous, rarely somewhat canescent be- 
neath, 2’-7’ long, 2-3” wide, the margins revolute when 
dry, the upper ones all alternate, the lower opposite; 
heads usually few, sometimes solitary, 2’-3’ broad; in- 
volucre hemispheric, its bracts linear-lanceolate, acute 
or acuminate, scarcely squarrose, pubescent; receptacle 
slightly convex; disk purple; chaff entire or 3-toothed; 
rays 12-20; achenes truncate, glabrous; pappus usually 
of 2 short awns. 
In swamps, Long Island, N. Y., to Florida, Kentucky and 
Texas, mainly near the coast. Aug.—Oct. 
4. Helianthus orgyalis DC. Linear-leaved 
Sunflower. Fig. 4464. 
H. giganteus var. crinitus Nutt. Gen. 2: 177. 1818? 
Helianthus orgyalis DC. Prodr. 5: 586. 1836. 
Perennial by slender rootstocks; stems glabrous, 
branched near the summit, very leafy to the top, 
6°-10° high. Leaves sessile, entire, linear or nearly 
filiform, or the lowest lanceolate, remotely dentate 
and short-petioled, rough with mucronate-tipped 
papillae, especially on the lower surface, acuminate, 
4-16’ long, 1-4” wide, the upper all alternate and 
I-nerved, the lower commonly opposite; heads nu- 
merous, about 2’ broad, terminating slender branches; 
involucre nearly hemispheric, its bracts linear-subu- 
late to lanceolate, acuminate, squarrose, ciliate; disk 
purple or brown; receptacle convex, its chaff entire, 
or toothed, slightly ciliate; rays 10-20; achenes ob- 
long-obovate, glabrous, 23”-3” long, 2-4-awned.. 
On dry plains, Missouri and Nebraska to Colorado 
and Texas. Sept.-Oct. 
5. Helianthus atrérubens L. Hairy Wood Sunflower. Purple-disk Sunflower. 
Fig. 4465. LA =\\Z, 
A SS 
Helianthus atrorubens L. Sp. Pl. 906. 1753. 
Perennial; stems hirsute below, often minutely pu- 
bescent above, branched at the summit, 2°-5° high. 
Leaves hirsute on both sides, or canescent beneath, 
mostly thin, ovate or ovate-lanceolate, acutish, con- 
tracted near the base into margined petioles, sometimes 
subcordate, dentate or crenate-dentate, 4’-10’ long, 1-4’ 
wide, the lower opposite, the upper few, distant, small, 
mainly alternate; heads not numerous, slender-pedun- 
cled, about 2’ broad; involucre hemispheric, its bracts 
oblong to obovate, obtuse, ciliolate, appressed; disk 
purple; recptacle convex, its chaff acute, entire, or 
3-toothed; rays 10-20; achenes obovate, truncate, finely 
pubescent, about 2” long; pappus usually of 2 lanceo- 
late awns. 
In dry woods, Virginia to Florida, west to Ohio, Mis- 
souri, Arkansas and Louisiana. Aug.—Oct. 
