211 COMPOSITES. (COMPOSITE FAMILY.) 



■»-••-*-+-■*- Leaves more or less prominently 3-ribbcd. 

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

 ened ; stein mostly simple ; leaves obscurely 3-ribbed ; the lowest spatulute- 

 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 G - 7 ; achenia hairy. — Old fields and open woods, common. 

 — Stem l°-2° high. 



37. S. Leavenworthii, Torr. «Sb 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, faintly 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 serrate 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. ChBYBOMA. — Stem shrubby: leaves impresseel-punclate, veinless : rays 1-3: 

 receptacle conical, naked. 



41. S. pauciflosculosa, Miehz. Stem, leaves, and involucre viscid: 

 leaves spatulate-lanccolatc or linear, obtuse, entire, the lowest scale-like; pani- 

 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. Rays 

 large. 



$4. Kt'TMAMiA. — 1I( rhacfoits : leaves narroir, entire, 1 - 5-nervr d : head* corym- 

 bose : rays more numerous than the disk-Jtowers : receptacle bristly : involucre 

 viscid. 



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

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



nerred ; 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 corymboscly much 

 branched : leaves linear, 3-nerved, glandular-dotted ; heads few in a fluster, 





