OF NORTH AMERICA. 
9 
the Missourian regions, with its vast central 
plains ; there they chiefly fringe the banks of 
streams, seldom forming groves and forests. 
This scanty dispersion prevails also more or 
less into the Origon Mts. and Shores, extending 
South to New Mexico, California, Texas and 
even Mexico ; where the thick extensive For- 
ests of the Alleghanian and Canadian regions 
are unknown. This straggling growth of Trees 
prevails also to a certain extent from Louisi- 
ana to Florida where groves are intermixt with 
meadows, glades, sand flats, cane brakes, 
swamps &,c, and even in the Western States, 
on both sides of the River Ohio, the trees are 
not so thick set, being far apart and with fewer 
shrubs for undergrowth. 
Of the extensive tribes of Composites, Cru- 
ciferous, Euphorbides, Alsinides, Dianthides, 
Geranides, &/c hardly any are shrubby in North 
America, while so many are such elsewhere. 
Our shrubby Vines belong chiefly to Sarmen- 
tacea, Rhamnides, Bignonides, Woodbines, 
Smilacea <$*c. 
All the tribes of European and Siberian trees 
or shrubs are found also in North America, and 
nearly all their Genera likewise, except the 
Heaths, Daphnes, and a few others. But the 
American Sylva can boast of a greater num- 
ber of species in all the Genera, with several 
peculiar tribes and many American Genera ; 
such as Liriodendron, Magnolia, Asimina.Ara- 
lia, Catalpia, Hamamelis, Fothergilla, Gordo- 
nia, Dirca, Diervilla, Comptonia, Hicoria, A- 
morpha, Gleditsia, Robinia, Cladrastis, Chi- 
onanthus, Cephalanthus &c. 
It is very remarkable that nearly all the A- 
merican trees, and shrubs except some boreal 
2 
