70 THE VEGETATION OF THE UNITED STATES. 



6. Southeastern Deciduous Trees. (Plates 17 and 18.) 



Quercus falcata Michx. (=Q. digitata Sudw.). 

 Sapindus marginatus Willd. 



These trees have been used as typical of the southeastern distribu- 

 tions, the former being very nearly coincident with the Atlantic Coastal 

 Plain in its range, the latter occupying its largest area in Texas and 

 Oklahoma, and extending eastward along the Gulf coast to Florida. 



7. Northern Deciduous Trees. (Plates 17 and 18.) 



Populus balsamifera L. (including P. hastata Dode). 

 Quercus macrocarpa Michx. 



These trees have been selected because of their wide northern range, 

 which is limited in the former to the eastern portion of the Northern 

 Evergreen Needle-leaved Forest and to a small area in the northern 

 Rocky Mountains, while the latter tree extends south to the inner 

 edge of the Coastal Plain and is remarkable for its extreme western 

 extension into the grassland region. 



8. Southeastern Evergreen Broad-Leaved Trees. (Plate 19.) 



Ilex opaca Ait. 



Magnolia grandiflora L. ( = M. foetida (L.) Sarg.). 



Ilex has been used as an example of an evergreen broad-leaved tree 

 which is nearly coincident in its range with the extent of the Atlantic 

 Coastal Plain, and Magnolia has been used as another tree of the same 

 growth-form which is confined to a more southern section of the Coastal 

 Plain. 



9. Palms. (Plate 20.) 



Sabal palmetto (Walt.) R. and S. 

 Serenoa serrulata (Michx.) Hook. 



Washingtonia filamentosa Wendl. ( = Neowashingtonia filamentosa (Wendl.) 

 Sudw.). 



The three palms which are most widely distributed in the United 

 States have been used as the sole representatives of this type of plant 

 and as groups which are confined to the warmest portions of the United 

 States. Sabal and Serenoa are both confined to western Florida and 

 the adjacent coasts, while Washingtonia is found only in the interior 

 deserts of southern California. 



10. Palustrine Shrubs. (Plate 22.) 



Cephalanthus occidentalis L. 



Adelia acuminata Michx. ( = Forestiera acuminata Poir.) 



Decodon verticillatus (L.) EIL 



Itea virginica L. 



