72 Annals of thk Carnegie Museum. 



=;- H. scabrum Michaux. Rough hawkweed. 



i H. Gronovii T.inn?eus. Hairy hawkweed. 



NABALUS Cassini. 

 PRENANTHES Linnsus. 

 -j- N. crepidineus (Michaux). Corymbed rattlesnake-root. 



* N. albus (Linnaius). White rattlesnake-root. 

 "^ N. serpentarius (Pursh). Lion's-foot. 



* N. altissimus (Linnaeus). Tall white lettuce, 

 f N. trifoliatus Cassini. Tall rattlesnake-root. 



TARAXACUM Haller. 



* T. Taraxacum (Linn?eus). Common dandelion. 

 T. offiiinalf Weber. 



§ T. erythrospermum Andrzejowski. Red-seeded dandelion. 



LACTUCA Linnseus. 



* L. Scariola Linnreus. Prickly lettuce. 



* L. Canadensis Linnseus. Wild lettuce. 



'■-'- L. sagittifolia Elliott. Arrow-leaved lettuce. 

 L. intei^rifolia Bigelow. 



* L. hirsuta Muhlenberg. Hairy wood-lettuce. 



^- L. villosa Jacquin. Hairy blue lettuce. 

 Z. acuminata A. Grav. 



