382 COMPOSITE. Helianthus. 



var. ambiguus : leaves nearly all opposite and closely sessile, obtuse and rounded at the 

 base. Torr. ^ Gr. I.e. 



Root perennial. Stem 4-8 feet high, paniculately branched at the summit, terete, purplish, 

 often smoothish below. Leaves 3-5 inches long, and from half an inch to an inch or more 

 broad ; in the var. ambiguus, there are often three or more leaves so close together that they 

 appear verticillate. Rays 15-20, sulphur-yellow, about an inch in length. 



Borders of swamps and in thickets ; common. The var. ambiguics, in a copse near Brook- 

 lyn. August - September. 



2. Helianthus strumosus, Linn. Wild Sunflower. 



Stem simple, or sparingly branched and roughly pubescent at the summit, smooth below ; 

 leaves opposite, ovate-lanceolate, with a long tapering point, serrate with small appressed teeth, 

 very rough above, whitish and usually softly pubescent underneath, somewhat triplinerved, 

 abruptly contracted into a short margined petiole ; scales of the involucre lanceolate, acuminate, 

 ciliate, equaling the disk, squarrose-spreading at the summit ; rays mostly 10. — Linn. sp. 2. 

 p. 905 ; Torr. ^ Gr. fl. N. Am. 2. p. 327. H. macrophyllus, Willd. Berol. t. 70 ; DC. 

 prodr. 5. p. 587. H. decapetalus, Darlingt. fl. Cest. p. 483. H. altissimus, DC. I. c. 

 (excl. ^.). 



Root perennial. Stem 2-4 feet high, slender, sprinkled with a few minute warts, a little 

 branched at the summit in a fastigiate manner. Leaves 3-6 inches long and 1-2 inches 

 wide, rather thick and firm, with indistinct serratures, green above ; the under surface always 

 whitish, and usually clothed more or less thickly with very short hoary pubescence, but 

 sometimes smooth ; the winged petiole about half an inch long. Heads of flowers commonly 

 3-5, on roughly pubescent stalks. Scales of the involucre conspicuously ciliate on the 

 margin ; the rest nearly smooth. Rays oblanceolate, an inch to nearly an inch and a half 

 long, bright yellow. Achenia smooth. Pappus consisting usually of two subulate chaffy 

 scales, and 2-3 much smaller ones. 



Thickets, dry woods, and rocky banks of rivers ; rather common. August - September. 



3. Helianthus decapetalus, Linn. Wild Sunflower. 



Stem smooth below, a little rough and branching above ; leaves opposite, ovate or oblong- 

 ovate, thin, abruptly contracted into a petiole, coarsely serrate, triplinerved ; scales of the 

 involucre narrowly lanceolate, loose, squarrose, hispidly ciliate, the exterior longer than the 

 disk ; rays 8 - 10. — Linn. sp. 2 p. 905 ; Hook. hot. mag. t. 3510; DC. prodr. 5. p. 588 ; 

 Torr. 4- Gr. fl. N. Am. 2. p. 328. H. strumosus and H. tenuifohus, Ell. sk. 2. p. 420. 

 H. multiflorus (partly), and H. frondosus, Hook. fl. Bor.-Am. 2. p. 312. H. frondosus, 

 Darlingt. fl. Cest. p. 483. 



