CARDUACEAE. 
383 
Leaves all entire or the lower merely toothed. 
V. Gnaphaloides. 
Leaves at least the lower ones pinnately divided or lobed. 
Divisions of the leaves not narrowly linear or filiform ; margins 
scarcely revolute. VI. Diversifoeiae. 
Divisions of the leaves narrowly linear to filiform; margins 
revolute. VII. Stenophyllae. 
Involucres in age glabrous, only slightly tomentose when young. 
VIII. Vulgares. 
Plant shrubby; leaves cuneate, 3-toothed at the apex. 
IX. Bigelovianae. 
Heads homogamous; i. e., flowers all alike, hermaphrodite and fertile; plants 
shrubby. X. Tridentatae. 
I. Dracunculoides. 
Plants frutescent only at the base; heads rather many-flowered, hemispherical, 
over 1.5 mm. in diameter. 
Plants glabrous, at least in age ; leaves all, except the lower ones, simple and 
linear. 
Leaves and bracts dark green ; heads 3-4 mm. wide ; flowers 30-40, brown. 
1. A. aromatica. 
Leaves and bracts lighter; heads 2-3.5 mm. wide; flowers yellow or light 
brown, about 20. 2. A. dracunculoides. 
Plant pubescent; leaves nearly all pinnatifid. 
Heads 2-3 mm. wide; bracts glabrous; stem appressed-hairy or glabrate; 
flowers yellow. 
Stem-leaves with 1-2 pairs of lateral divisions close at the base, or entire 
grayish canescent. 3. A. glauca. 
Stem-leaves pinnatifid or bipinnatifid with distant divisions, mostly green 
at least in age. 
Stem tall, 5-10 dm. high, very leafy, in age nearly glabrous; divisions 
of the leaves linear-filiform. 4. A. Scouleriana. 
Stem lower, 2-6 dm. high ; divisions of the basal leaves linear-oblanceo- 
late, more or less canescent. 5. A. Foncoodii. 
Heads 4-5 mm. wide ; bracts and stem at least when young with long silky- 
villous loose hairs ; flowers brown. 6. A. spithamaea. 
Plant shrubby; heads few-flowered, 1-1.5 mm. in diameter; divisions of the 
leaves filiform. 7. A. dlifolia. 
II. Frigidae. 
Heads numerous, 4-5 mm. wide ; bracts light brown ; plants usually comparatively 
tall, 3-8 dm. high. 8. A. frigida. 
Heads few, 6-12 mm. in diameter; bracts with dark brown or blackish margins; 
plant low, 1-2 dm. high. 
Heads several, spicately or racemosely disposed; corolla pubescent; basal 
leaves and lower stem-leaves bipinnatifid. 9. A. scopulorum. 
Heads solitary or 2-4 in a close cluster; corolla glabrous or nearly so ; basal 
A. Pattersonii. 
11. A. biennis. 
leaves pinnatifid with short divisions. 
10. 
• 
III. Annuae. 
One species. 
IV. Arcticae. 
11. 
Plant pubescent. 
12. 
Plant glabrous. 
V. Gnaphaloides. 
13 - 
Leaves in age glabrate above. 
14 - 
Leaves permanently tomentose 
on both sides. 
Heads erect, peduncled, 4-5 
mm. wide ; flowers 
brown . 15. 
14. A. silvicola. 
Heads nodding or spreading, 4 111m. or less wide. 
