THISTLE FAMILY 977 



5. ^. pumila. 



6. yl. granulifcra. 



7. ^. gracilis. 



Plant 1-2 dm. (rarely 3 dm.) high; leaves thick, subentire. or witl 

 linear-lanceolate. 



III. Granulifer-ye. 



One species. 



IV. Graciles. 



Upper leaves not linear. 



Bracts linear-lanceolate; leaves thin, usually more or less dentate. 



Bracts oblanceolate ; leaves thick, usually entire. 8. A. pubcrula. 



Upper stem-leaves hnear, much reduced. 9. A, arnoglossa. 



• V. Latifollve. 



Leaves decidedly hairy, especially above. 10. A. Jonesii, 



Leaves nearly glabrous. ■, .^, . ^^ j , - i 



Achenes slightly glandular-granuhferous, and with a few scattered hairs above. 



Leaves not saliently toothed, merely denticulate. 11. A, ventonim. 



Leaves saUently and coarsely toothed. 12. A. Memiesii, 



Achenes glabrous; leaves more or less toothed. 13. A. lalifolia, 



YI. DiVERSIFOLIAE. 



Leaves thin, nearly glabrous. . , . x, II* 4* V-^^^^^fP\- 



Leaves thick, densely glandular-puberulent, at least above. 15. A. dirersifoha, 



VII- LONGIFOLIAE. 



Involucre merely puberulent or gland ular-granuliferous; leaves not caudate-attenuate; 



stem usuaUy over 3 dm. liigh. . . , ^ ^ ^^' ^* I'^^^^f^^^^- 



Involucre copiously hirsute, as well as puberulent; leaves caudate-acummate. 



17. A. caudata. 



VIII. MOLLES. 



Involucre villous, not at all glandular or viscid. 18. A. macilenta. 



Involucre more or less glandular or viscid. ' 



Involucre densely glandular-granuhferous, only with a few white hau^s. 



Involucre decidedly villous or hirsute, as well as glandular. 



Middle stem-leaves broadly ovate, less than 5 cm. long; stem 2-3 dm. high 



Involucre less than 1 cm. high, villous at the base, only shghtly glandular; 

 bracts broadly lanceolate. ^ ^ ■ ^. ^ 20, A, coloradensis. 



Involucre 12-15 mm. liigh, densely glandular-hirsute; bracts narrowly ob- 

 lanceolate ^■^- ^- o^(^^^' 

 Middle stem-leaves lanceolate, oblanceolate, or linear-lanceolate. 



Bracts oblanceolate, abruptly acuminate. 22. A. mollis. 



Bracts linear or lanceolate. , ^ ^ 4. 4, xi, i. 



Stem-leaves more or less sharply dentate, except at the base. 

 Leaves nearly glabrous, except the margins. 



Stem-leaves ovate-lanceolate, broad at the base. , .^ ,. 



23. A, ample It folia. 



Stem-leaves oblanceolate or narrowly lanceolate, narrowed at the 

 base ^'^' ^* ^^O-counii. 



Leaves decidedly pubescent, both \^ous and glandular-granuliferous. 



25. A. rivularis. 



Stem-leaves entire, sparmgly denticulate, densely glandular-puberulent. 



IX. Folios.^. 



Plnnt densely pubescent with fine hairs; leaves acute or obtuse. 

 ^^"^ Lef v^ broad^ oblanceolate or lanceolate. 29. A, rhtzom^^^^ 



Leaves linear or lance-hnear. <>"■ -^- joiiosa, 



^'''^^^^LrX^l^rS^^:''^A^^l^e or callous-denticulate; involucre rarely 



Pub^°cenceonheSvSre and peduncle very short ^^ 31. A. ocreata. 



P^hScInce of the involucre and peduncle longer and coarser. 32. A. celsa. 

 Ste^l^vTb^oad^y lanceolate, more or less dentate; mvolucre i^ual^y mo^^than 1 



cm. high. 



20, A. color adensis. 

 Stem-leaves ovate. 

 Stem-leaves linear to lanceolate. 



^^'^Jn^offie^^d^aclVS^JeTl^ glandular-pubertUent ; achen^ ^^^J^-^; 

 involucre more or less yiUous. at least at the base; ^^^^^^^^^ 



bracts green. 



bracts green. ., , , -^4 4 Rudberaii 



Leaves strongly S^ribbed. 34 A. ^vaoergxi. 



Leaves 



35 



