2 12 coMrosn^E. (composite family.) 



Var. strictula, Torr. & Gray. Stem simple, or with few elongated rough- 

 pubescent branches; leaves smaller ; racemes short, forming a long and slender 

 compound raceme. (S. salicina, EU.) — Swamps, Florida, ami northward. 



Sept. and Oct. — Stem 4°-G° high. 



24. S. arguta, Ait. Smooth; leaves sharply serrate, acute or acuminate 

 at each end, the lowest elliptical or lanceolate-oblong, somewhat 3-ribbcd, on 



winged and eiliate petioles ; the upper sessile ; panicle dense, somewhat corym- 

 bose; heads small, crowded, 1 8 - 20-flowercd ; rays 8-12, small; scales of the 

 involucre obtuse ; achenia nearly smooth. (S. juncea, Ait., a form with narrower 

 and less strongly sen - ate leaves, the upper ones entire.) — Rich soil in the upper 

 districts. Sept. — Stem 2° - 4° high. 



25. S. Boottii, Hook. Stem smooth, or pubescent above; leaves lanceo- 

 late or oblong, acute or acuminate at each end, apprcssed-scrrate, smooth or 

 more or less pubescent; panicle open, oblong or pyramidal; heads about 12- 

 nowered; rays 5; scales of the involucre obtuse; achenia nearly smooth. — Va- 

 ries, with longer, narrower, ami more sharply serrate leaves, and slender racemose 

 panicles towards the summits of the spreading branches. (S. juncea? Ell.) — 

 Sandy soil, Florida to North Carolina. Sept. — Stem 2°-3° high, often pur- 

 plish. Heads larger and leaves more rigid than in the last. 



2G. S. gracillima, Torr. & Gray. Smooth ; stem slender ; lowest leaves 

 Bpatulate-lanceolate, obtuse, serrate near the apex ; the others linear and entire ; 

 heads rather large, 9- 12-flowered, forming a narrow compound raceme at the 

 summit of the stem and branches ; rays mostly wanting ; scales of the involucre 

 oblong, obtuse; achenia pubescent. — Dry pine barrens, Middle Florida. Oct. 

 — Stem 2° high. 



*-•*-■*- Leaves very numerous, gradually diminishing in size upward, veiny, sessile, 

 or the lowest narrowed into a short petiole : heads small. 



27. S. altissima, L. Stem hirsute; leaves ovate or oblong, acute, serrate, 

 rough above, pubescent, especially on the veins beneath, often rugose, promi- 

 nently veined ; panicle leafy, often narrow and elongated; the racemes slender 

 and recurved ; scales of the 10— 15-flowered involucre linear; rays (*>-9, small ; 

 achenia pubescent. (S. rugosa, S. ulmifolia, and S. aspera, Ell.) — Low thick- 

 ets, Florida, and northward. Sept and Oct. — Stem 2° -6° high, commonly 



branching. Leaves variable in texture and pubescence, being thin and smoother 

 in shady places, and more rigid, rougher, and often rugose in placet more c.\- 

 posed. 



28. S. ulmifolia, Muhl. Stem smooth, or softly pubescent above ; leaves 

 ovate-lanceolate, acuminate, senate, smooth on the upper surface, paler and pu- 

 bescent on the veins beneath ; panicle loose, spreading ; heads about lO-flowon '1 ; 



rays 4—5; scales of the involucre acutish; achenia nearlj a >th. — Low 



ground in the upper districts of Alabama, and northward. Sept. — Stem 2° -3° 

 high. Leaves thin, 2'-8' long. 



20. S. Elliottii, Torr. & Gray. Smooth; stem mostly simple; leaves 

 oblong-lanceolate or elliptical, sessile, acute, finely Berrate, the upper often 



entire-; racemes crowded, forming a pyramidal panicle; scales of the 13-20- 



