52 THE VEGETATION OF THE UNITED STATES. 



DECIDUOUS TREES OF THE SOUTHEASTERN UNITED STATES. (PLATE 4.) 



On the basis of the literature descriptive of the vegetation of the 

 southeastern United States, a group of fifteen deciduous broad-leaved 

 trees has been selected as representative of this vegetation form in 

 that section of the country. The cumulative distribution of the fifteen 

 trees which have been selected is shown in plate 4. 



These trees are of interest because they are extremely common in 

 the Atlantic Coastal Plain and are nearly all either infrequent in the 

 Piedmont and Allegheny regions or are absent there. These trees are, 

 in short, representatives of the deciduous habit which have their 

 maximum cumulative occurrence as well as their maximum abundance 

 outside the deciduous forest area and in the heart of the Southeastern 

 Mesophytic Evergreen Forest. Five of the species used are palustrine 

 and nearly all of them occupy other habitats than those in which the 

 evergreen needle-leaved trees are dominant. The following is a list 

 of the species which have been used in the construction of the map 

 shown in plate 4: 



Acer drummondii Hook, and Am. 



Fraxinus caroliniana Mill. 



Hieoria aquatica (Michx. f.) Britton. 



Liquidambar styraciflua L. 



Nyssa aquatica L. 



Nyssa ogeche Marsh. 



Planera aquatica (Walt.) Gmel. 



Populus heterophylla L. 



Quercus brevifolia (Lam.) Sarg. 

 Quercus catesbsei Michx. 

 Quercus digitata (Marsh.) Sudw. 

 Quercus michauxii Nutt. 

 Quercus pheUos L. 

 Quercus texana Buckl. 

 Uhnus alata Michx. 



CUMULATIVE DISTRIBUTION OF THE COMMONEST EASTERN DECIDUOUS TREES. 



(PLATE 5.) 



A selection has been made of the thirteen deciduous trees which are 

 commonest in the Deciduous Forest area and are most widely dis- 

 tributed throughout it. These are all large forest trees which are 

 wholly deciduous throughout their ranges and are commonly found in 

 upland habitats. The maximum occurrence of this group is in the 

 region extending from central New York to northern Alabama, com- 

 prising the entire extent of the Allegheny Mountains. From this 

 region, in which 13 of the species are found, the abundance of this group 

 shades off to the east, south, and west, so that the area in which from 

 12 to 8 species are found covers the Coastal Plain of Virginia and Caro- 

 lina, extends south to western Florida, and west as far as the eastern 

 boundaries of Texas, Kansas, and Minnesota. The following is a 

 list of the thirteen species that have been used in the preparation of 

 this map, shown in plate 5 : 



Acer saccharum Marsh. 

 Carpinus caroliniana Walt. 

 Castanea dentata (Marsh.) Borkh. 

 Fagus atropunicea Ehrh. 

 Fraxinus americana L. 

 Hieoria glabra (Mill.) Britton. 

 Hieoria minima (Marsh.) Britton. 



Juglans nigra L. 

 Liriodendron tulipifera L. 

 Quercus alba L. 

 Quercus prinus L. 

 Quercus velutina Lam. 

 Ulmus americana L. 



