INDEX 



WHIPPLEA 

 modesta 



WYETHIA 

 ampiexicaulis 

 hellanthoides 

 lanceolata 

 robusta 



XANTHIUM 

 Canadense 

 strumarium 

 spinosum 



XYLOSTEON 

 conjugialis 



206 involucratum 



206 Ledebourii 



340 Utahensis 



341 villosum 



340 ZANNICHBLLIA 



3*1 palustris 

 341 



337 

 337 

 337 

 338 

 281 

 282 



XEROPHYLLUM 



Douglasil 



tenax 

 ZIZIA 



cordata 



268 



