COMPOSITE, (composite family.) 255 



38. L^PACHYS, Raf. ( Obehscaria, DC. ) 



Heads many-flowered, radiate ; the rays few, neutral. Scales of the involucre 

 few and small, spreading. Receptacle oblong or columnar : the chaif truncate, 

 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 grcfoved stems or branches naked above, terminated by single showy 

 heads. Rays yellow or party-colored, drooping ; the disk grayish. (Name from 

 XfTTif, a scale, and tra^vs, thick, from the thickened tips of the chaff'. ) 



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

 (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, W. New York (Dr. Sartwell), to Wisconsin and southward.' July. — 

 The receptacle exhales a pleasant anisate odor when bruised. Achenia slightly 

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



39. HELIANTHUS, L. Sunflowee. 



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

 imbricated. Receptacle flattish or convex ; the persistent chafi' embracing the 

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

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

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

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

 wards autumn. (Named from ^Xtos, the sun, and avdos, ajiower.) 



§ 1. Boot annual: leaves cdtemate : receptacle Jiat : disk brownish. 



1. H. ANNtJos, L. (Common Sunflowek.) 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. Amer.) 

 § 2. Root perennial, the creeping rootstocks sometimes tuberous-thickened or tuberiferous. 



» Disk convex, dark purple .• leaves mainly opposite ; heads small, except No. 4. 



2. H. angustifblius, L. Stem slender (20-6° high) ; leaves long and 

 linear, sessile, entire, with revolute margins, 1 -nerved ; heads loosely corymbed, 

 long-peduncled ; scales of the involucre tapering into narrow and spreading her- 

 baceous tips. — Low pine barrens. New Jersey to Kentucky and southward. 



3. H. atrdrubens, L. Rough-hairy; stem s/«n(fer (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 ; scales of the involucre ovate, obtuse, regularly imbri- 

 cated, appressed, destitute of herbaceous tips; rays 10-16; pappus of 2 fringed 

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



4. H. rigidUS, Desf. Stem stout (I0-3° 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; scales of the involucre ovate or lance-oblong, 

 obtuse, ciliate, appressed, destitute of herbaceous tips ; rays 20 - 25 ; pappus of 2 

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

 westward. 



