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 \enis, a scale, and iva\vt, thick, referring to the thickened tips 

 of the chaff.) 



1. Li. pillliatcl, Toit. & 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 arc 2' long). — 

 Dry soil, from Chatauquc County, New York (Sartwell), to Wisconsin and 

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

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



30. HELIANTHVS, L. Sunflower. 



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

 Imbricated. Itcceptacle flattish or convex ; the persistent chaff embracing the 

 4-sided and laterally compressed achenia, which arc 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 rp\ios, the sun, and avdos, 

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



# Disk convex, dark purple : leaves opposite, or the tipper alternate. 

 t- Scales of the involucre tapering into narrow and spreading herbaceous tips. 



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

 linear, sessile, entire, with rcvolute margins, 1-nerved, pale beneath ; head's 

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

 Kentucky and southward. 



*- i- Scales of the involucre regularly imbricated and appressed, ovate or broadly 

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



2. H. atrorubens, L. Bough-hairy; stem slender (2° -5° high), smooth, 

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

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

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

 nois, and southward. 



3. II. rigidus, 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 appressed, 

 with someivhat spreading and acute (but not foliaceous) tips : leaves chiefly opposite. 



4. H. IsetifldrilS, Pers. Stout and rough (3° - 4° high ), branching above ; 

 leaves oval-lanceolate, very rough both sides, narrowed into short petioles, serrate, taper- 

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



