214 compositjE. (composite family.) 



f- -1- H- -1- 1- Leaves more or 'ess prominently 3-ribbed. 



36. S. nemoralis, Ait. Plant grayish, minutely pubescent and rough- 

 ened ; stem mostly simple ; leaves obscurely 3-ribbed ; the lowest spatulate- 

 oblong or lanceolate, serrate ; the upper lanceolate, acute, narrowed toward the 

 base, mostly entire ; panicle dense, oblong or pyramidal, recurved ; heads 10 - 

 12-flowcred ; rays 6-7 ; achenia hairy. — Old fields and open woods, common. 

 — Stem l°-2° high. 



37. S. Leavenworthii, ToiT. & Gray. Stem simple, minutely pubescent 

 and roughish ; leaves very numerous, smooth, linear-lanceolate, entire ; the low- 

 est sparingly serrate; panicle pyramidal; heads rather large; rays 10-12; 

 achenia pubescent. — Damp soil, Florida to South Carolina. Oct. — Stem 2° - 

 3° high. Leaves 2' -3' long, 3" -4" wide, ftiintly ribbed. 



38. S. Canadensis, L. Stem pubescent and often rough ; leaves lanceo- 

 late, acute or acuminate, sharply serrate, rough above, pubescent beneath ; pan- 

 icles pyramidal, dense ; heads small ; rays very short ; achenia pubescent. — 

 Varies (S. procera, Ell.), with a more hairy stem, less sen'ate leaves, the upper 

 entire, and larger heads and rays. — Margins of fields, &c. Florida, and north- 

 ward. Oct. — Stem 3° - 8° high. 



39. S. Serotina, Ait. Stem smooth, often purple ; leaves lanceolate, acu- 

 minate, serrate, rough above, pubescent on the veins beneath ; panicle pyramidal, 

 of numerous recurved racemes ; rays short ; mature achenia smooth. — Low 

 ground, Florida, and' northward. Oct. — Stem stout, 4° - 8° high. Heads 

 larger than in the last, but smaller than those of the next species. 



40. S. gigantea, Ait. Stem smooth ; leaves smooth, lanceolate, acumi- 

 nate, sharply serrate, rough on the margins ; panicle large, pyramidal, pubes- 

 cent; rays small; achenia pubescent. — Margins of fields, &c., Alabama, and 

 northward. Sept. and Oct. — Stem 2° - 6° high. 



§ 3. Chkysoma. — Stem shrubby: leaves impressed-punctate, veinless: rays 1-3: 

 receptacle conical, naked. 



41. S. pauciflosculosa, Michx. Stem, leaves, and involucre viscid; 

 leaves spatulate-lanceolate or linear, obtuse, entire, the lowest scale-like; paiii- 

 cle 1-sided; the clusters erect, on naked peduncles ; heads 4 -7-flowered; scales 

 of the involucre obtuse ; achenia pubescent. — Sandy banks and shores, Florida 

 to South Carolina. Oct. — Stem l°-2° high. Leaves l'-2' long. Eays 

 large. 



§ 4. EuTHAMiA. — Herbaceous: leaves narrow, entire, 1 -5-nerved: heads corym- 

 bose : rays more numerous than the dish-Jlowers : receptacle bristly : involucre 

 viscid. 



42. S. lanceolata, L. Stem pubescent above, corymbose ; leaves linear- 

 lanceolate, roughish on the upper surface, pubescent on the veins beneath, 3-5- 

 nerved ; heads obconical, mostly sessile, in dense clusters ; rays 15-20. — Damp 

 soil, Georgia, and northward. — Stem 2° -3° high. 



43. S. tenuifolia, Pursh. Nearly smooth ; stem corymbosely much 

 branched ; leaves linear, 3-nerved, glandular-dotted ; heads few in a cluster. 



