notes by botanists, foresters, biologists, and 
other workers. However, since not all of the 
unpublished notes have been supported by 
authenticated herbarium specimens, an effort 
has been made to include only reports of qualified 
observers. 
Nomenclature of the species, both scientific 
and common names, and the order of arrange- 
ment, follow the Check List. Since the issuance 
of that publication in 1927, certain minor revi- 
sions in the standard nomenclature have been 
adopted by the Forest Service. These have been 
incorporated in the present publication along 
CHECK LIST—continued 
Abies concolor Lindley and 
Gordon. 
Abies amabilis (Loudon) 
Forbes. 
Chamaecy paris nootkatensis 
(Lambert) Sudworth. 
Populus trichocarpa Hooker. 
Ostrya virginiana (Miller) 
Koch. 
Betula lutea Michaux. 
Betula populifolia Marsh. 
Gymnocladus  dioicus 
naeus) Koch. 
Acer nigrum IF. A. Michaux. 
(Lin- 
CORRECTION—continued 
Abies concolor Lindley. 
Abies amabilis (Douglas) 
Forbes. 
Chamaecy paris nootkatensts 
(Lambert) Spach. 
Populus trichocarpa Torrey and 
Gray. 
Ostrya virginiana (Miller) K. 
Koch. 
Betula lutea Michaux filius. 
Betula populifolia Marshall. 
Gymnocladus  dioicus  (Lin- 
naeus) K. Koch. 
Acer nigrum Michaux filius. 
Although collection of data has continued for 
with other minor corrections listed below. 
CHECK LIST 
Pinus monticola D. Don. 
Pinus balfourtana Murray. 
Pinus resinosa Solander. 
Pinus ponderosa Lawson. 
Pinus jeffreyi ‘““Oreg. Com.” 
Pinus contorta Loudon. 
Picea engelmannit Engelmann. 
Pseudotsuga  taxifolia 
Marck) Britton. 
(La 
CORRECTION 
Pinus monticola Douglas. 
Pinus balfourtana A. Murray. 
Pinus resinosa Aiton. 
Pinus ponderosa Douglas. 
Pinus jeffreyt Greville and 
Balfour. 
Pinus contorta Douglas. 
Picea engelmanni (Parry) 
Engelmann. 
Pseudotsuga taxifolia (Lam- 
bert) Britton. 
many years, the records are still incomplete. 
One of the objectives of the present publication, 
therefore, is to stimulate interest in the acecumu- 
lation of more accurate information on the dis- 
tribution of our North American trees. The 
Forest Service will welcome data indicating the 
need for changes on the present maps. Location 
data should be as specific as possible to facili- 
tate plotting, and occurrence should be sub- 
stantiated by herbarium specimens when their 
collection is practicable. 
