224 THE FLORA. 
g Ach. with along beak, pap. silk-white. Heads erect. c. Wild Lettuce. Lactvu’oa. 
g Achenia not beaked, pappus dull-white. Hds. nod. ¢. Drop-jflower. Nax’atus. 10 
g Achenia not beaked, pap. dull-white. Hds. erect, purple. 8. 7. Lyeopxs’s1a. 
Achenia of Asterworts, showing the varying pappus. Fiég. 518. Ac2enium of Eclipta, m 
pappus, Fig. 519. Horseweed (Ambrosia trifida). Fig. 520. Sunflower; pappus 2 teeth 
Fig. 521. Ageratum,—5 scales. Fig. 522. Blue Lettuce,—many hair-like bristles. ig. 523. 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. Receptacle 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. bicolor, whitish), 
opening from August to October. (See Figs. 501-503.) 
{ Shrub woody, 1-8f. high. Heads with 1-8 rays. 8....1 
Herbs. Heads without rays (discoid). §8....2, 8 
{| Herbs. Heads with rays (1-15, generally small)....a 
a Scales of the involucre with recurved, leafy, green tips....4, 5 
a Seales of the invotucre erect, tips scarcely at all green....b 
b Herbs (white or yeilow) in axillary, close clusters or short racemes... ,6-9 
b Heads in terminal racemes forming a close or a spreading panicle....¢ 
b Heads in terminal compound corymbs....n 
c Racemes erect, not one-sided. Leaves feather-veined....d 
c Racemes 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....e 
e Plants very smooth, at least the stem and leaves. Rays 4-7....18-15 
e Plants downy or hoary with very close soft hairs. Rays 9-12....16, 17 
Leaves 8 or l-veined. Very smooth salt-marsh herbs....18, 19 
f Leaves evidently 3-veined. Herbs inland, &c....g 
f Leaves not veiny, thick, subcutive....27-29 
f I.eaves evidently feather-veined, mostly serrate....k 
