(63) 



aa. Branches of the style flat and tipped 

 with an appendix. 



aaa. Parts of pappus GO. 



1. Bigelovia. Involucre imbricate: scales 

 dry. Pappus 1-seriate, capillary, at 

 maturity brownish. Ray flowers yellow. 



2. Aplopappus. Involucre imbricate, 

 scales foliaceous. Pappus 1-seriate, 

 bristles rigid. Bay flowers yellow. 



3. Chrysopsis. Involucre imbricate. Pap- 

 pus 2-seriate, internal capillary, external 

 scaly. Bay flowers yellow. 



4. Lessingia, Kay flowers enlarged but 

 not ligulate. 



5. Solidago. Involucre imbricate, scales 

 foliaceous. Pappus silky. Kay flowers 

 yellow. 



6. Aster. Involucre imbricate, scales foli- 

 aceous. Kay flowers not yellow, 1-seri- 

 ate. 



7. Erigeron. Involucre imbricate, scales 



foliaceous. Kay flowers not yellow, 

 co-seriate. 



bbb. Parts of pappus definite in number, 



1. Pentachseta. Scales of involucre not her- 

 baceous. Pappus of 5 scabrous bristles 

 shorter than the corolla, sometimes de- 

 pauperate. Kays yellow. 



