COMI'OSlTyK. (composite FAMILY.) 255 



38. Ll^PACHYS, Kaf. (Oreliscaiua, 7)C.) 



Heads inaiiy-ll<i\vciT(l, radiate ; tlie rays few, neutral. Scales of the involucre 

 few and small, sjireadiii;;. lvece])tacle oijionj^j or coluinuar : the chall' tiuniate, 

 thickened and iicarded at the U\>, partly euil)racin<^- the tlattened and niar;;ined 

 achenia. l'ai)i)us none or J teeth. — I'erennial herb.s, with alternate pinnate 

 leaves; the grooved steins or hranehes naked above, terminated by single showy 

 lieads. Ka\'s yellow or ])urty-eolored, drooping ; the disk grayish. (Name from 

 XfTTf?, a si-iilr, and nax^s, tliir/c, from the thickened tips of the chaff.) 



1. L. pinnita, Torr. & Gr. Hoary with minute appressed hairs, slender 

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

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

 Dry soil, W. New York {Dr. Sdiiircll), to Wisconsin and southward. July. — 

 The receptacle exhales a ])leasant anisate odor when bruised. Aehcnia slightly 

 margined on the inner edge, obscurely 2-toothcd at the top. 



39. HELIANTHUS, L. Sunflower. 



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

 imbricated. Ueceptacle flattish or convex ; the persistent chatf endjracing the 

 4-sidi.'d and laterally compressed achenia, which are neither winged nor mar- 

 giiicd. ra])pus very deciduous, of 2 thin chaffy scales on the principal angles 

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

 stout herbs, with solitary or corymbcd heads, and yellow rays ; flowering to- 

 wards autumn. (Named from tjXios, the sun, and uv6os, ujiower.) 



§ 1. Root annual : leaves alternate : receptacle Jlat : disk biownish. 



1. H. ANNUL-.S, L. (CoMMox SuNFLOWER.) Tall, rough ; leaves triple- 

 ribbed, ovate or the lower heart-shaped ; heads in cult, plant very broad, and 

 rays many. — Escaped from cult, into waste grounds. (Adv. from trop. Anier.) 

 § 2. Hoot perennial, the creeping roofstocks sometimes tuberous-thickened or tulicrijlrous. 



* Disk convex, dark purple: leaves mainly opposite: heads small, except Xo. A. 



2. H. angUStif61ius, L. Stem slender (20-60 high); leaves lonij and 

 linear, sessile, entire, with revolute nnvrgins, 1-nerved ; heads loosely corynd)cd, 

 long-fledunilc.l ; scales of the involucre tapering into narrow and spreading hcr- 

 baceons tii)s.— Low pine barrens, New Jersey to Kentucky ami southward. 



.}. H. atr6rubens, L. RnMjh-hairii ; stem s/pWe/- (20-50 high), smooth, 

 and naked and forking above ; hacrs thin, orate or oral, or the lowest heart- 

 shajjcd (.'J'-G' long), serrate, abruptly contracted into a margined jx-tiolc ; 

 lieads small, corymbcd ; scales of the involucre ovate, obtuse, regularly indiri- 

 cated, (fy»/)ms-,sW, destitute of herlmcous tips; rays 10-16; pai)i)us of 2 fringed 

 scales. — Dry soil, Virginia, Illinois, and southward. 



4. H. rigidus, Dcsf. Stem stout (l°-3° high), simple or sparingly 

 branched, rough ; leaves veri/ thick and rigid, rough lioth sides, Monij-lunceolate, 

 usually pointed at both cinls, nearly sessile, slightly serrate, the lowest ovnl ; 

 heads nearly solitary, pretty large; scales of the involucre ovate or lance-oblon;;, 

 obtu.se, eiliate, appressed, r/'.s7///(/,' of herhacout tips: rays 20-25; p.i|)pus of 2 

 large and often several small scales. — Dry prairies, Aliehigan to Hlinois, and 

 westward. 



