ee ae 
Statistics of the Flora of the Northern United States. 205 
crosses the parallel is Jussiea repens, This sparingly extends up 
Ses about as 
far north as on the Atlantic coast, 
In the elevated region through which the middle of our 
southern boundary passes, great numbers of northern plants are 
of course found to extend much farther southwar 
er. 
The northern boundary, being that between the United States 
and British America, varies through about five degrees of lati- 
tude, and nearly embraces Canada proper on the east and on the 
. * It would apparently exclude from the flora of the Northern States the follow- 
1es — 
ing spec 
Gordonia Lasianthus. Benzoin melissefolium. 
Stuartia Virginica. Tetranthera geniculata, 
Zanthoxylum Carolinianum. Stillingia sylvatica. 
Berchemia volubilis. Quercus virens. 
Viburnum o um. “ cinerea. 
Mitreola petiolata. Sagittaria falcata. 
Liatris odoratissima. Burmannia biflora, 
panicula Tillandsia usneoides, 
Sericocarpus tortifolius. Smilax Walteri. 
Chrysopsis gossypina. " ceolata, | 
Baccharis glomeruliflora, Zygadenus glaberrimus, 
Kalmia hirsuta, Mayaca Michauxii. 
ex ine. Pepalanthus flavidus, 
“ myrtifolia, Lachnocaulon 
n, Vilfa Virgini 
emium sempervirens, Ctenium Ameri 
Forsteronia diffurmis, Uniola paniculata. 
Olea Americana, : Paspal istichur 
Fraxinus platycarpa. gitar 
Carol: 
little beyond lat. 388° 30’. Two other characteristic trees, viz, the Palmetto and 
Magnolia grandiftora, stop about as far short of our line as the two former pass 
