72 Annals of ihe Carnegie Museum. 



* H. scabrum Michaux. Rough hawkweed. 



t H. Gronovii Linnaeus. Hairy hawkweed. 



NABALUS Cassini. 

 PRENANTHES Linnc^us. 

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



* N. albus (Linnaeus). 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 (Linnaeus). Common dandelion. 

 T. officinale Weber. 



§ T. erythrospermum Andrzejowski. Red-seeded dandelion. 



LACTUCA Linnffius. 



* L. Scariola Linnaeus. Prickly lettuce. 



* L. Canadensis Linnaeus. Wild lettuce. 



* L. sagittifolia Elliott. Arrow-leaved lettuce. 

 L. intei^rifolia Bigelow. 



* L. hirsuta Muhlenberg. Hairy wood-lettuce. 



■^ L. villosa Jacquin. Hairy blue lettuce. 

 L. acuminata A. Gray. 



