(66) 



B. Receptacle paleaceous. 



a. Anthers obtuse or sagittate at their 

 base, but never calcarate. 



aa. Involucre 1-seriate or nearly so. 



1. Iva. ? flowers reduced to short tubes 

 embracing the base of the style. flow- 

 ers: anthers scarcely connate. 



2. Balsamorrhiza. Akenes of the disc 4-an- 

 gular. Pappus 0. 



3. Wyethia. Akenes 4-angular or laterally 

 compressed. Pappus paleaceous, crown- 

 shaped. 



4. Pugiopappus. Akenes villous. Pappus 

 2-aristate. 



5. Leptosyne. Akenes naked, margined. 

 Pappus almost 0. 



6. Madia. Involucre in a simple row, each 

 scale wrapped about a laterally com- 

 pressed akene. Pappus 0. 



7. Holozonia. Involucre in a simple row, 

 each scale completely embracing an 

 akene. Pappus of the ray akenes hya- 

 line, of the disc generally 0. 



8. Hemizonia. Involucre 1-seriate, each 

 scale embracing with its base half of a 

 ray akene. Pappus of the ray 0. 



