Hills of S. Dak., extreme ne. Wyo., and e. to nw. and e. Nebr., lowa, 
n. Mo., Ohio, W. Va., and N. J., also local in sw. Va. and w. Ky. 
156. Viburnum nudum L., possumhaw viburnum. Coastal Plain, 
chiefly, from s. Conn., Long Is., N. J., and sw. Pa., to c. Fla., w. to 
e. Tex., and n. to c. Ark. and w. Tenn. 
157. Viburnum obovatum Walt., Walter viburnum. Coastal Plain 
from e. S. C. to c. and nw. Fla. 
158. Viburnum prunifolium L., blackhaw. Sw. Conn. and se. 
N. Y., w. to s. Mich., extreme se. Wis., Ill., and sw. lowa, s. to 
e. Kans. and c. Ark., and e. to Tenn., Ala., and S. C. 
159-N, 159-NE. Viburnum trilobum Marsh., American cranberry- 
bush. Nfld., N.S. (Cape Breton Is.), P. E. 1, N. B., ands. Que., w. to 
s. Ont., and s. Man., s. to N. Dak., Black Hills and ne. S. Dak., and e. 
to ne. lowa, n. Ill.. Pa., and N. J., and local in W. Va. and n. Va. Also 
local in s. Alta., s. B. C., and Wash. 
160. Viburnum rufidulum Rat., rusty blackhaw. Se. Va. w. to 
Ky., s. Ohio, s. Ind., c. Mo., and e. Kans., s. to c. Okla. and e. and 
e. Tex., and e. to n. Fla. 
161. Yucea aloifolia L., aloe yucca. Coastal dunes and mounds 
from se. N. C. to s. Fla. including Fla. Keys and w. to s. Ala. 
162. Yueca gloriosa L., moundlily yucca. Coastal dunes and 
beaches from ne. N. C. to se. Ga. and extreme ne. Fla. 
163. Zanthoxylum americanum  Miill., 
.N.H., Vt., and sw. Que., w. to s. Ont., n. Mich., n. Minn., and 
e. N. Dak., s. to c. Nebr. and c. Okla., e. to S. C., and n. to sw. Va., 
PasvanduN, | 
164-N, 104-SE. Zanthoxylum fagara (L.) Sarg., lime prickly-ash. 
C. and s. Fla. including Fla. Keys, and se.. s., and sw. Tex. Also West 
common 
prickly-ash. 
op) 
Indies from Bahamas to Cuba and Hispaniola and n. Mex. (Lamps. to 
Coah., s.Son., and s.B. Cal. Sur, southward) s. to C. Am. and 
S. Am. 
165. Zanthoxylum clava-herculis L., Hercules-club. Coastal Plain 
from e. Va. to s. Fla. and w. to e. Tex., and n. to se. Okla. and 
c. Ark. 
166. Zanthoxylum hirsutum Buckl., Texas Hercules-club. 5. Okla. 
s. to s. and sw. Tex. and ne. Mex. (n. Tamps. and n. N. L.). 
NOTES ON RANGES 
Some observations on tree distribution may be noted from the 
maps of the 166 species in this volume. However, analyses of the 
ranges are outside the scope of the Atlas. An attempt has been made 
to record where each species grows naturally now, not to explain or 
speculate how and why. 
Many maps show distinctive or unusual ranges. Especially note- 
worthy are the species of farthest geographic extent and greatest 
variation in environmental conditions. Some species may be widely 
adapted to many types of climates. Others apparently are composed 
of geographic races. 
Relatively few species have broad east-west distribution nearly 
across the continent and can be classed as transcontinental. The 
widespread conifers and important hardwoods were mapped in 
Volume |. Twenty species of this volume extend westward beyond 
the maps of the 37 Eastern States. Western ranges of the same 
species have been shown in Volume 3. These minor hardwood 
species of broad east-west distribution are listed below. Four that 
range northwest to Alaska are designated by an asterisk (*). 
*Amelanchier alnifolia, western serviceberry 
Bumelia lanuginosa, gum bumelia 
Cephalanthus occidentalis, common buttonbush 
Cercis canadensis, eastern redbud 
*Cornus stolonifera, red-osier dogwood 
Corylus cornuta, beaked hazel 
Crataegus succulenta, fleshy hawthorn 
Prunus americana, American plum 
Prunus angustifolia, Chickasaw plum 
Prunus pensylvanica, pin cherry 
Prunus virginiana, common chokecherry 
Ptelea trifoliata, common hoptree 
Rhus glabra, smooth sumac 
*Salix bebbiana, Bebb willow 
Salix discolor, pussy willow 
*Salix exigua, coyote willow 
Salix petiolaris, meadow willow 
Sapindus drummondit, western soapberry 
Viburnum lentago, nannyberry 
Viburnum trilobum, American cranberrybush 
One shrubby species, Cornus stolonifera, red-osier dogwood. 
reaches from central Alaska across Canada to Newfoundland and 
south to the Northeastern States and in western mountains to 
northern Mexico. Another, smooth sumac, Rhus glabra, is the only 
species classed as sometimes reaching tree size and native in all 48 
contiguous States and also in adjacent Canada and Mexico. However. 
it has been found in California only once and in Nevada at only two 
localities. 
Nearly all tree species of this volume are confined to North 
America, but a few tree species, mostly northern or subtropical, 
extend beyond. Cephalanthus occidentalis, common buttonbush, 
ranges from southeastern Canada and south through Mexico into 
Central America and in Cuba. The same or a closely related species is 
recorded from eastern Asia. 
Species found near sea level in the North rise to higher altitudes 
southward. These northern trees reach their southern limits in the 
Southern Appalachians, where they are classed as mountain species. 
Overlay 3, Topographic Relief, in Volume 1, has contour lines. 
which may indicate some relationships in distribution. Endemic. 
disjunct, and northern trees in the Southern Appalachians have been 
discussed elsewhere (Little 197 1b). 
Other species are southern and characteristic of the Gulf and 
Atlantic Coastal Plains. Many of these extend northward along the 
Atlantic coast, some to New England or beyond. Inland, some 
project up the Mississippi Valley. 
Eleven common tree species of Eastern United States cited in 
Volume | reappear southward on mountains of Mexico or also 
Central America, sometimes as distinct botanical varieties or under 
separate names. Several species of the southeastern Coastal Plain 
mapped in this volume are present also in the Coastal Plain or 
mountains of Mexico or Central America or beyond. Illustrations 
are: 
Cyrilla racemiflora, swamp cyrilla 
Hamamelis virginiana, witch-hazel 
Ilex cassine, dahoon 
Ilex decidua, possumhaw 
Ilex vomitoria, yaupon 
Illicium floridanum, Florida anise-tree 
Myrica cerifera, southern bayberry 
Osmanthus americanus, deyilwood 
Rhamnus caroliniana, Carolina buckthorn 
A few tree species of the southeastern Coastal Plain reappear in 
Cuba or beyond in the West Indies, sometimes as a named variety. 
(Nearly all the tropical tree species of South Florida, to be mapped 
in Atlas Volume 5, are also widely distributed in the West Indies.) 
11 
