224 



THE FLORA. 



g Aoh. with a long beak, pap. silk- white. Heads erect, v. Wild Zettuce. 'LiOTv'ci. 

 g Aohenia not beaked, pappus dull-white. Hd.i. nod. v. Drop-flower. Nab'alus. 10 

 g Aohenia not beaked, pap. duU-wliite. Hds. ereet, purple. S. r. Lt&odes'mia. 



531 523 519 520 518 522 



Aohenia of Asterworts, showing the varying pappus. Mg. 518. Achenium of Eolipta, no 

 pappus. Mg. 519. Horseweed (Ambrosia trifida). Fig. 520. Sunflower; pappus 2 teeth. 

 fig. 621. Ageratuin,— 5 scales. Mg. 522. Blue Lettuce,— many hair-like bristles. Mg. 623. Wild 

 Lettuce, pappus raised on a beak. 



1. SOLIDA'GO. Goldenrod. 

 Heads few-flowered, the rays 1-15, pistillate, disk florets^ perfect. In- 

 volucre oblong, imbricate, with close-pressed scales. Eeceptacle alveo- 

 late, narrow. Pappus simple, of equal, hair-like, rough bristles. — Herbs, 

 very abundant in the United States. Stem erect, branching near the top. 

 Leaves alternate. Heads small, florets' all yellow (in S. bioolor, whitish), 

 opening from August to October. (See Tigs. 501-S03.) 



t Shrub woody, l-3f. high. Heads with 1-S rays. S 1 



1 Herbs. Heads without rays (discoid). S 2,8 



H Herbs. Heads with rays (1-15, generally small).... « 



a Scales of the involucre with recurved, leafy, green tips.... 4, 5 

 a Scales of the involucre erect, tips scarcely at all green. . . .b 



b Herbs (white or yellow) in axillary, close clusters or short racemes 6-9 



b Heads in terminal racemes forming a close or a spreading panicle. . . .u 



b Heads in terminal compound corymbs. . . .ii 



c Racemes erect, not one-sided. Leaves feather-veined d 



c EacemcB spreading or recurved, the flowers all on one side. . . .f 



d Alpine species (growing only on mountains). Heads quite large. . . .10-12 



d Not alpine — growing in plains or low grounds. Heads not large . . . .» 

 c Plants very smooth, at least the stem and leaves. Kays 4-7 . . . .13-15 

 e Plants downy or hoary with very close soft hairs. Eaya 9-12 .... 16, 17 



f Leaves 3 or 1-veined. Very smooth salt-marsh herbs. . . .18, 19 



f Leaves evidently 3-veined. Herbs inland, &0 g 



f Leaves not veiny, thick, subcutive .... 27-29 



f Leaves evidently feather-veined, mostly serrate k 



