CARDUACEAE. 

 Leaves all entire or the lower merely toothed. 



V. GXAPHALOIDES. 



Leaves at least the lower ones pinnately divided or lobed. 



Divisions of the leaves not narrowly linear or filiform ; margins 



scarcely revolute. VI. DIVERSIFOLIAE. 



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. BlGELOVIANAE. 



Heads homogatnous ; i. e., flowers all alike, hermaphrodite and fertile ; plants 

 shrubby. X. TRIDEXTATAE. 



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. 



i. A. aromatica. 

 Leaves and bracts lighter : heads 2-3.5 mm. wide ; flowers yellow or light 



brown, about 20. 2. A. dracuncnloides. 



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. Fonvoodii. 



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. filifolia. 



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 

 leaves pinnatifid with short divisions. 10. A. Pattersonii. 



III. ANNUAE. 



One species. n. A. biennis. 



IV. ARCTICAE. 



Plant pubescent. 12. A. saxicola. 



Plant glabrous. 13. A. Parry i. 



V. GNAPHALOIDES. 



Leaves in age glabrate above. 14. A. silvicola. 



Leaves permanently tomentose on both sides. 



Heads erect, peduncled, 4-5 mm. wide; flowers brown. 15. A. iiatroiicnsis. 



Heads nodding or spreading, 4 mm. or less wide. 



