4 
All of the sources used for the distribution maps of the 
European and Asian pines are listed with the species notes. 
Additional source material, not listed with species notes, was 
used for the pines of the United States, for those of Califor- 
nia in particular, and for the pines of Canada and Mexico. 
United States.—Sargent (1884) was perhaps the first to 
record in detail the distribution of the native trees of the 
United States, including the genus Pinus, and to publish 
distribution maps of a few native pines. Afterwards he pub- 
lished revised ranges without maps in his Silva (1891-1902) 
and Manual (1905, 1922, 1926). Mohr (1897) prepared 
maps of the species of Pinus in southeastern United States. 
Early work by the Forest Service on tree distribution 
maps has been reviewed by Little (1951). In charge of this 
work was George B. Sudworth, dendrologist with the former 
Bureau of Forestry from 1886 to 1905 and with the Forest 
Service thereafter until his death in 1927. Sudworth sum- 
marized ranges in his Check Lists (1898, 1927) and cited 
detailed distribution records in his Forest Trees of the Pacific 
Slope (1908). He and his assistants prepared distribution 
maps of most native tree species for publication under the 
title, “Forest Atlas Geographic Distribution of North Amer- 
ican Trees.” Only Part I—Pines (Sudworth 1913), contain- 
ing maps for 36 species of Pinus, appeared. Some smaller 
maps were issued in five bulletins on Rocky Mountain trees: 
one of them covered the pines (Sudworth 1917) . 
Munns (1938) published 170 maps of important forest 
trees of the United States, including 26 of pines, revised from 
Sudworth’s older maps. Many of these maps were redrafted 
on a smaller scale and often with slight revisions in the Forest 
Service leaflets known as the American Woods series, several 
on pines, by Betts (1945). New small maps of 165 species 
including 20 pines were made for the 1949 Agriculture Year- 
book, Trees (Little 1949). An atlas showing the distribution 
of the native tree species is in preparation (Little 1951). 
The revised maps of the 36 species of Pinus native in the 
United States published here have incorporated with  re- 
visions the Forest Service maps prepared for other publica- 
tions. These include maps of 18 species for the book, “‘Silvics 
of Forest Trees of the United States” (Fowells 1965), and 
maps for the forthcoming atlas. 
In compiling these maps, the earlier Forest Service maps 
and other references mentioned above have been consulted, 
and the sources for the small maps in the 1949 Yearbook 
have been rechecked (Little 1951). 
Current State floras (Blake and Atwood 1942; Gunn 
1956) and tree books (Dayton 1952), several with maps by 
species and detailed range notes, have been important sources 
for plotting distribution on a large base map of the United 
States showing county boundaries. Some local floras have 
been checked, especially to fill in any gaps in State publica- 
tions. Regional floras and tree publications have been helpful 
also. Maps of several native tree species, including a few 
pines, have appeared in monographic studies. Some general 
references for tree identification contain small maps. 
Several State herbaria possess unpublished maps for each 
species showing by dots the counties or localities of the speci- 
mens collected. Credit is due the curators for permission to 
use this unpublished information. Where other records 
seemed inadequate, some herbarium specimens have been 
examined, for example, in a few States without species maps 
and for uncommon species of imperfectly known range. 
The Forest Survey of the Forest Service has provided 
much detailed information on the distribution of commercial 
tree species. From measurements of trees on thousands of 
uniformly spaced sample plots within a State, highly accurate 
maps have been compiled, especially for the southeastern 
species (Janssen and Weiland 1960). States with distribution 
maps of commercial tree species published by the Forest Sur- 
vey include: Virginia (Evans 1942), North Carolina (Roberts 
and Cruikshank 1941a), South Carolina (Roberts and Cruik- 
shank 1941b), and Mississippi (Sternitzke and Duerr 1950). 
Similar unpublished records of pines and other conifers by 
counties for other Southeastern States have been consulted. 
Some very early western forest survey reports contained 
species maps not duplicated later. Forest type maps prepared 
mostly by the Forest Service have been published by States or 
regions. These have been helpful in mapping limits of 
dominant tree species, associated trees, and nonforested areas, 
particularly in western States of great altitudinal range and 
vegetation zonation. Vegetation maps have been prepared 
for some States, and one of the United States by Zon and 
Shantz (1924). 
Accuracy of the latest maps has been improved through 
review by many foresters, both within the Forest Service and 
outside, and by botanists. Their assistance is acknowledged. 
Principal ‘sources, published and unpublished, for the 
maps of the 36 species of Pinus native in the United States are 
summarized below by States. California, with additional spe- 
cial sources, is discussed separately. Pinus is not native in 
Hawaii, Kansas, or Puerto Rico. 
Alabama.—Harper (1928); Mohr (1901). ; 
Alaska—Hultén (1941); Sudworth (1908) ; Taylor and Little 
(1950). 
Arizona.—Kearney and Peebles (1960); Little (1950). Un- 
published maps by Robert A. Darrow at University of 
Arizona Herbarium. 
Arkansas.—Moore (1960). Unpublished maps by Dwight M. 
Moore at University of Arkansas Herbarium. 
California—Jepson (1910); Munz and Keck (1963); Sud- 
worth (1908). Special sources are cited on page 4. 
Colorado.—Cary (1911); Harrington (1954). Unpublished 
maps by H. D. Harrington at Colorado State University 
Herbarium. 
Connecticut.—Graves et al. (1910) ; Taylor (1915). 
Delaware.—Taber (1960); Tatnall (1946). 
District of Columbia.—Hermann_ (1946); 
Standley (1919). _ 
Florida—Kurz and Godfrey (1962); Ward (1963); West and 
Arnold (1956). 
Georgia.—Bishop (1948); Harper (1907-08); Thorne (1954) . 
Unpublished maps by Wilbur H. Duncan at University of 
Georgia Herbarium. 
Idaho.—Davis (1952); Johnson (1961) ; 
Merriam (1891); St. John (1963). 
Hlinois—Jones and Fuller (1955); Miller and Tehon (1929). 
Indiana.—Deam (1940); Deam and Shaw (1953). 
Towa.—Aikman and Hayden (1938); Campbell (1956). 
Kentucky.—Braun (1943): Garman (1913). Unpublished 
maps by Edward T. Browne, Jr., at University of Kentucky 
Herbarium. 
Louisiana.—Brown (1945); Cocks (1921). 
Maine.—Hyland and Steinmetz (1944); Ogden, Steinmetz, 
and Hyland (1948). 
Maryland.—Shreve et al. (1910); Tatnall (1946). Examina- 
tion by Russell G. Brown of specimens at University of 
Maryland Herbarium. 
Massachusetts—Emerson (1875); Illick (1927). 
Michigan —Otis (1931): N. Smith (1952). Unpublished 
maps by John W. Andresen from specimens at University 
of Michigan Herbarium, Michigan State University Her- 
barium, and other herbaria. 
Minnesota.—Rosendahl and Butters (1928). Specimens ex- 
amined at University of Minnesota Herbarium. 
Mississippi—Lowe (1921); Sternitzke and Duerr (1950). 
Missouri.—Settergren and McDermott (1962); Steyermark 
(1963). 
Hitchcock and 
Kirkwood (1930); 
Montana.—Booth (1950); Hutchison and Kemp (1952); Kirk- 
wood (1930); Rydberg (1900); Standley (1921) 
Nebraska.—Pool (1951). 
Nevada.—Billings (1954): Linsdale, Howell, and Linsdale 
(1952): Little (1956). 
New Hampshire.—Foster (1941) 
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