Examples from this volume are: 
Baccharis halimifolia, eastern baccharis (var. in Cuba) 
Cephanthus occidentalis, common buttonbush 
Cyrilla racemiflora, swamp cyrilla (to Puerto Rico and northern 
South America) 
Fraxinus caroliniana, Carolina ash (var. in Cuba) 
Ilex cassine, dahoon (to Puerto Rico) 
Myrica cerifera, southern bayberry (to Puerto Rico) 
Salix caroliniana, Coastal Plain willow 
RARE AND LOCAL EASTERN 
HARDWOODS 
The maps of this Atlas show clearly which tree species are 
confined to limited geographic areas. From these trees of local 
occurrence, lists of rare and endangered species may be compiled. 
The subject of rare and endangered trees is being teated in a series of 
separate publications. 
The first report, “Rare and Local Conifers in the United States” 
(Little 1975) is based upon Volume | and contains maps of 35 
species from that source. Similarly, the species maps of Volumes 3 
and 4 reveal much information about rare and endangered hard- 
woods. A summary of the species in eastern continental United 
States (exclusive of southern Florida and southern Texas) may be 
appropriate here. Rare tropical trees of south Florida will be treated 
in Volume 5 and in a separate report (Little 1976b). 
The Endangered Species Act of 1973 (U.S. Public Law 93-205, 
approved December 28, 1973) directed the Smithsonian Institution 
to prepare a list of endangered and threatened plant species, to 
review methods of adequately conserving these species, and to report 
the Institution’s recommendations to the Congress. Accordingly, the 
Secretary presented to the Congress on December 15, 1974, its 
200-page “Report on Endangered and Threatened Plant Species of 
the United States” (Smithsonian Institution 1975). As explained in 
the foreword by Secretary 5. Dillon Ripley, this preliminary report 
provides lists of proposed endangered, threatened, recently extinct, 
and exploited species of native plants of the United States. 
However, the Act also provides that the Secretary of the U.S. 
Department of the Interior must study the Smithsonian Institution’s 
preliminary lists of species and determine whether or not any species 
is truly threatened or endangered. At this time, no species has 
officially been so classified by the Secretary. The Fish and Wildlife 
Service (1975) published the list as a notice of consideration for 
review of status and inyitation for proposals. Thus, the threatened 
and endangered species mentioned below are tentative or prelimi- 
nary and will remain so until the Secretary makes a final 
determination—possibly several years in the future. 
The preliminary lists for continental United States comprise about 
10 percent of the flora, or 2,099 species (including some varieties 
and subspecies). Fortunately, the number of tree species and 
varieties is small, only about 32 (also L1 varieties), of which 13 are 
eastern hardwoods mapped in Volume 4. The number of species of 
rare trees is somewhat larger. 
Next, a few definitions. A rare species has small numbers of 
individuals throughout its range, which may be restricted or 
widespread. The term local species (also endemic) is used here for a 
species of relatively small range, such as a small part of a State ora 
few islands. Border or peripheral species reach the limit of their 
natural range a short distance into the United States, for example, 
from Mexico into the Southwest or from the West Indies to Florida. 
12 
An extinct species (recently or possibly extinct) is no longer known 
to exist after repeated search of the type locality and other known 
or likely places. 
As defined in the Act, “the term endangered species means any 
species which is in danger of extinction throughout all or a 
significant portion of its range...” “The term threatened species 
means any species which is likely to become an endangered species 
within the foreseeable future throughout all or a significant portion 
of its range.” 
Only about 23 species of minor eastern hardwoods of the 166 
mapped in Volume 4 have relatively small ranges in the United 
States and may be classed under one or more of the above terms. 
Several rare varieties are not mapped separately or mentioned. South 
Florida has a large number of rare trees, border or peripheral species, 
which are also found in the West Indies or in Mexico, and thus they 
are not endangered at present. 
The list of recently extinet species of higher plants in continental 
United States (Smithsonian Institution, 1975, p. 38-47) contains 
about 100 kinds. However, the two trees listed, both mapped in this 
volume, still exist. 
Franklinia alatamaha, franklinia, is the symbol of the endangered 
plant program and appeared on a botanical commemorative postage 
stamp in 1969. This large shrub or small tree named for Benjamin 
Franklin was discovered in 1765 by John and William Bartram but 
has not been seen wild since 1790. The original colony near Fort 
Barrington on the Altamaha River, McIntosh County, southeastern 
Georgia, probably was exterminated by transplanting the cultivation 
and thus saved. This species is classed as extinct in the wild but is 
also in cultivation for its large white flowers. 
Betula uber, Ashe birch, was classed as probably extinct until 
rediscovered in 1975. It was named in 1918 from Smyth County, 
southwestern Virginia. Rediscovery was reported by Ogle and 
Mazzeo (1975, 1976) and Reed (1975). The last concluded that the 
few trees found on private land had been planted and that they 
probably hybrid birch, B. 
alleghaniensis Britton, and low birch B. pumila L. var. glandulifera 
represented — the between yellow 
Reg., and known also as Purpus birch, B. Xpurpusii C. K. Schneid. If 
shown to be an artificial hybrid, this birch should be removed from 
lists of both native and rare trees. 
The 23 species of hardwoods with local distribution in eastern 
continental United States (exclusive of southern Florida and 
southern Texas) are mapped in Volume 4. These mostly southern 
species (also several local varieties not listed or mapped separately) 
may be grouped geographically in the four lists below. Of the 13 on 
the lists compiled by the Smithsonian Institution, | is designated as 
extinct except in cultivation, 3 are designated endangered, and 9 are 
classed as threatened. 
Southern Appalachians (or slightly beyond) 
Betula uber, Ashe birch (formerly classed as extinct) 
Castanea ozarkensis, Ozark chinkapin (Ozark Mountains) 
(endangered) 
Cladrastis kentukea, yellowwood 
Cotinus obovatus, American smoketree (to Ozarks and Texas) 
Prunus alleghaniensis, Allegheny plum (threatened) 
Quercus georgiana, Georgia oak (Piedmont) (threatened) 
Quercus oglethorpensis, Oglethorpe oak (Piedmont) (threatened) 
Robinia kelseyi, Kelsey locust 
