216 COMPOSITE, (composite family.) 



thickened, and bearded at the tip, partly embracing the flattened and margined 

 achenia. Pappus none, or 2 teeth. — Perennial herbs, with alternate pinnate 

 leaves ; the grooved stems or branches naked above, and terminated by single 

 showy heads. Rays yellow or party-colored, large and drooping ; the disk gray- 

 ish. (Name from XeTTi's, a scale, and naxis: thick, referring to the thickened tips 

 of the chaff.) 



1. li. piimata, Torr. & Gr. Hoary with minute appressed hairs, slen- 

 der (4° high), branching; leaflets 3-7, lanceolate, acute; disk oblong, much 

 shorter than the large and drooping light-yellow rays (which are 2' long).: — 

 Dry soil, from Chatauque County, New York {Sartwell), to Wisconsin and 

 southward. July. — The receptacle exhales an anisate odor wlion bruised. 

 Achenia slightly margined on the inner edge, obscurely 2-toothed at the top. 



39. HEL.IANTHIJS, L. Sunfloweh. 



Heads many-flowered, radiate ; the rays several or many, neutral. Involucre 

 imbricated. Receptacle flattish or convex ; the persistent chaff embracing the 

 4-sided and laterally compressed achenia, which are neither winged nor mar- 

 gined. Pappus very deciduous, of 2 thin chaffy-awned scales on the principal 

 angles of the achenium, and often 2 or more little intermediate scales. — Coarse 

 and stout herbs (often exuding a resin), with solitary or corymbed heads, and 

 yellow rays : flowering towards autumn. (Name from ^Xios, the sun, and apdos, 

 u flower.) — All our wild species are perennial. 



* Disk convex, dark purple : leaves opposite, or the upper alternate. 

 ■t- Scales of th£ involucre tapering into narrow and spreading herbaceous tips. 



1. H. angUStifoIJUS, L. Stem slender (2°-6°high); leaves long and 

 linear, sessile, entire, with revolute margins, 1-nerved, pale beneath ; heads 

 (small) loosely corymbed, long-peduncled. — Low pine barrens. New Jersey to 

 Kentucky and southward. 



■f- ■>- Scales of the involucre regularly/ imbricated and appressed, ovate or broadly 

 lanceolate, obtuse, ciliate, destitute of herbaceous tips. (Leaves nearly all opposite.) 



2. H. atrorubeilS, L. Rough-hairy; s<em sicnrfer (2° -5° high), smooth, 

 and naked and forking above ; leavei thin, ovate or oval, or the lowest heart-shaped 

 (3'-6' long), sen-ate, abruptly contracted into a margined petiole; heads small, 

 corymbed; rays 10-16; pappus of 2 fringed scales. — Dry soil, Virginia, Ken- 

 tucky, and southward. 



3. H. rig^idus, Desf. Stem stout (l°-3° high), simple or sparingly 

 branched, rough ; leaves very thick and rigid, rough both sides, oblong-lanceolate, 

 usually pointed at both ends, nearly sessile, slightly serrate, the lowest oval ; 

 heads nearly solitary, pretty large; rays 20-25; pappus of 2 large and often 

 several small scales. — Dry prairies, Michigan to Illinois, and westward. 



# * Disk convex, yellow : scales of tlie involucre regularly imbricated and oppressed, 

 with somewliat spreading and acute {but not foliaceous) tips : leaves chiefly opposite. 



4. H. laetifloi'US, Pers. Stout and rough (Z°-i° high), hra.n(ihmgahoya; 

 leaves oval-lanceolate, very rough both sides, turn-owed into short petiole's, serrate, taper- 

 pointed, the uppermost alternate and nearly entire ; heads single or corymbed, 



