(CI) 



2. Aplopappiis. — IiiYolucre imbricate. Pap- 

 pus 1-seriate. Bristles rigid. 



3. Clii'jsopsis. — Involucre imbricate. Pap- 

 pus 2-seriate, internal capillary, external 

 scaly. 



4. Lessingia. — Pvay-flowers enlarged, but 

 not ligulate. 



5. Baccharis. — Dioecious. Shrub. 



bbb. Parts of pappus definite in num- 

 ber. 



1. Pentachfeta. — Pappus of 5-scabrous 

 bristles, shorter than the corolla, some- 

 times depauperate. 



2. Grindelia. — Pappus aristate. 



cc. Branches of style not flat, hut tap- 

 ering, sometimes luitli an appendix, 



aaa. Scales of the involucre herbaceous. 



1. Chaenactis. — Pappus paleaceous. 



2. Senecio. — Pappus capillar}^ 



bbb. Scales of the involucre scaynous. 



1. Artemisia. — Receptacle slightly convex. 

 Pappus 0. Akenes obovate with small 

 epigynous disc. 



2. Tanacetum. — Eeceptacle slightly convex. 

 Pappus 0. Akenes costate with large 

 epigynous disc. 



