Duplicate copies of notes and publications may be sent to the 
Forest Service for its map files, further reference, and possible future 
revision. Address: USDA Forest Service, Timber Management 
Research, P.O. Box 2417, Washington, DC 20013. 
STATISTICAL SUMMARY OF THE ATLAS 
“Atlas of United States Trees’’ in 6 volumes has maps compiled to 
show the natural range of the native tree species of continental 
United States. A statistical summary with numbers of species and 
maps follows. 
“Volume 1, Conifers and Important Hardwoods”’ has 201 species, 
including 94 of conifers and 107 of hardwoods (also 2 shrub species 
of conifers). A map of North America is added for 67 species (also 2 
shrub species of conifers). Also, 27 species (and | shrub species) have 
maps for both the Eastern and Western United States. There are 4 
base maps and 9 transparent overlays, for a total of 313 maps (all 
black-and-white). 
“Volume 2, Alaska Trees and Common Shrubs’’ has 38 tree 
species, including 6 shrub species of willow (Salix) that rarely reach 
tree size (also 44 more of common shrubs, making 82 species maps in 
color). It also has 23 general maps (8 in color) for a total of 105 maps. 
All Alaska tree species except 7 shrub species that rarely reach tree 
size are also in another volume. 
“Volume 3, Minor Western Hardwoods’”’ has 210 species. A map 
of North America is added for 62 species (including 2 Alaska species 
not native in the contiguous United States). Also, 15 species have 
both northeastern and southwestern maps. There are 4 base maps, 
for a total of 289 maps (all in color except base maps). 
“Volume 4, Minor Eastern Hardwoods”’ has 166 species (including 
19 also in Volume 3). A map of North America is added for 42 species 
(including 12 also in Volume 3). Also, 18 species have both northeast- 
ern and southeastern maps. There are 4 base maps, for a total of 230 
maps (all in color except base maps). 
“Volume 5, Florida’’ has 262 species on 129 pages. There are large 
maps of this State for 98 species of tropical hardwoods confined mostly 
to the southern part (6 also in other States). This volume repeats the 
Florida portion (with a few maps slightly revised) of 170 species from 
Volume 1, 3, and 4 (mostly 6 to a page). Also, there are 6 general 
maps for a total of 268 maps (all in color except 4 general maps). 
“Volume 6, Supplement”’ has small maps of 35 species of Crataegus, 
hawthorn; on 10 pages and | additional species (Juniperus erythro- 
carpa). Also, there are 3 base maps for a total of 39 maps (all black- 
and-white). 
Together, the 6 volumes contain 1,244 maps, or 1,081 pages of 
maps, including 53 general and base maps. 
So, the number of tree species native in continental United States, as 
defined and mapped here, is about 684. This number includes some 
shrub species rarely attaining tree size and often omitted from tree 
lists. Also counted are 98 species of tropical hardwoods, all but 6 of 
which are confined to southern Florida and are native in no other State. 
Native conifers total 95 tree species (also 2 shrub species), all in 
Volume | except for 1 addition in Volume 6. The 22 species of mono- 
cotyledons that reach tree size are mapped with the hardwoods in 
Volumes 1, 3, 4, and 5. The palm family, Palmae, has 11 native 
species of palms (1 southwestern and 10 southeastern). Tree-size yuccas, 
genus Yucca, total 11 (9 southwestern and 2 southeastern). So, as com- 
piled in this atlas, about 567 species are hardwoods (dicotyledons). Also 
charted are the Alaska ranges of 41 other species of common shrubs. 
Volume 6 has indexes of common names and scientific names of 
all species maps in Volumes 1-6. 
