330 CARDUACEAE. 



Bracts of the involucre herbaceous or partly colored, not striate. 



S. Laciniaria. 

 Bracts of the involucres not herbaceous, striate-nerved. 

 Pappus-bristles plumose ; anthers distinct ; bracts few. 



3. KUHNIA. 

 Pappus-bristles scabrous or barbellate ; anther united ; bracts usually many. 



4. COLEOSANTHUS. 



Tribe 3. ASTEREAE. 

 A. Plants not dioecious. 



I. Marginal pistillate flowers, if present, ligulate. 

 a. Ray-flowers yellow or none. 



1. Pappus consisting of scales or awns or lacking, never of numerous 



capillary bristles. 

 Heads small, not over 4 mm. high, few-flowered ; pappus more or less 



paleaceous. 6. Gutierrezia. 



Heads large, many-flowered ; involucre in all except one species viscid ; 



pappus of a few deciduous awns. 7. Grindelia. 



2. Pappus at least in part of numerous capillary bristles. 



u,. Pappus double, the inner of capillary bristles ; the outer of scales or 

 short bristles ; involucres many-flowered, hemispherical with narrow 

 imbricated bracts. 8. Chrysopsis. 



6. Pappus wholly of capillary bristles. 



* Heads discoid. 



Involucres narrowly turbinate ; its bracts more or less chartaceous, 

 keeled, arranged in definite (usually s) vertical ranks ; achenes 

 elongated-linear ; stigma-tips subulate-filiform. 



9. Chrysothamnus. 

 Involucres broadly turbinate to hemispherical ; its bracts more or 

 less imbricated, but not in definite vertical ranks ; achenes 

 scarcely elongated-linear. 

 Stigma-tips obtuse ; involucral bracts narrow, poorly imbricated. 



(Rayless species of) 31. Erigeron. 

 Stigma-tips acute ; bracts either broad or well imbricated or both. 

 Achenes truncate at the top, gradually tapering towards the 

 base, usually cinereous-pubescent ; bracts neither broad nor 

 abruptly acuminate. 

 Appendages or tips of the styles filiform ; undershrubs with 

 white-tomentulose stems and glandular-hairy foliage ; leaves 

 entire-margined. 15. Macronema. 



Appendages or tips of the stigmas subulate to ovate. 



Leaves with spinulose-tipped teeth ; corolla-tube slender. 



(Rayless species of) 11. Sideeanthus. 

 Leaves not spinulose, in ours entire-margined ; corolla- 

 tube dilated above. 10. Isocoma. 

 Achenes elongated, obovoid, i. e., tapering at both ends, but 

 more so below, multi-striate, glabrous or slightly hairy; 

 bracts of the involucres broad and abruptly acuminate ; ap- 

 pendages of the stigmas ovate to short-subulate. 



13. OONOPSIS. 



* Heads radiate. 



Leaves pinnately cleft or toothed ; lobes or teeth spinulose-tipped. 

 Pappus of the fertile achenes deciduous in a ring ; annuals, 

 equally leafy throughout ; bracts more or less foliaceous. 



14. Prionopsis. 

 Pappus persistent. 



Bracts chartaceous, not foliaceous, merely with green tips; 

 plants annual or perennial with a caudex, equally leafy 

 throughout ; pappus in age more or less spreading ; achenes 

 turbinate and densely silky. 11. Sideranthus. 



Bracts more or less foliaceous, at least above ; plants perennial 

 with taproots, large basal leaves and few and rather small 



