Plants of Europe naturalized in the United States. 151 



28* Salix vitellina. c Very generally met with, but I doubt if they 

 29* Salix alba. \ propagate naturally. 



30 Cannabis sativa. Very common, but not in quantities. 



31 Leonurus cardiaca. Very generally diffused. 



The asterisk marks such as have been originally introduced for some 

 medical or other special use. No other intentionally introduced plants 

 have taken root extensively in the country, unless some under the next 

 subdivision ought to be arranged here. Those which are naturalized in 

 confined localities are mentioned in the last rubric but one. 



2. Introduced fortuitously with agricultural seeds. 



N. B. Most of these (often noxious) have a still more decided claim to 

 be called naturalized, than the preceding ones, on account of their pre- 

 valence. 



32 Veronica arvensis. Every where. 



33 Veronica agrestis. Somewhat less frequent. 



34 Poa annua. Very general. 



35 Bromus secalinus. Every where. 



36 Setaria glauca. In the remotest regions. 



37 Triticum repens. Rare southwardly. 



38 Lolium perenne. Every where. 



39 Plantago lanceolata. Do. 



40 Chenopodium album. Do. 



41 Allium vineale. More or less prevalent, but met with almost every 



where. 



42 Polygonum aviculare. Absolutely every where. 



43 Cerastium vulgatum, ■\ 



44 Cerastium viscosum, > Do. 



45 Cerastium semidecandrum, * 



46 Agrostemma githago. Do. 



47 Hypericum perforatum. Southwardly and westward of the moun- 



tains this noxious weed is beginning to show itself. 



48 Lamium amplexicaule. The same remark holds good of this. In 



Carolina I traced its spread onward for more than fifty miles in 

 ten years. 



49 Antirrhinum linaria. Not yet beyond Pittsburg, nor southwardly 



frequent. 



50 Thlaspi bursa pastoris. Every where. 



51 Commelina sativa. Do. 



52 Rapkanus raphani strum. Every where. 

 Vol. III. 20 



