To Know the Trees 



IMPORTANT FOREST TREES OF THE 

 UNITED STATES 



ELBERT L. LITTLE, JR. 



FOR A SELECTED LIST of 165 

 important native forest tree spe- 

 cies of the United States the following 

 information is compiled here : ( 1 ) Ap- 

 proved common and scientific names, 

 as well as other names of lumber and 

 other names in use; (2) drawings, keys, 

 and nontechnical descriptive notes for 

 identification; (3) distribution maps 

 showing ranges; and (4) lists of prin- 

 cipal uses, chiefly of the wood. This 

 summary is intended as an introduc- 

 tion to the forest trees, as well as a 

 compilation of their distribution and 

 commercial uses. 



Trees are considered here as woody 

 plants having one well-defined stem or 

 trunk at least 2 inches in diameter at 

 breast height, a more or less definitely 

 formed crown of foliage, and a height 

 of at least 10 feet. Though the division 

 between trees and shrubs is not sharp, 

 shrubs typically are the smaller woody 

 plants, usually with several branches 

 from the ground instead of one trunk. 



The kinds, or species, of native trees 

 in the United States number about 

 845, excluding hybrids and varieties 

 but including smaller trees not of com- 

 mercial timber size and those classed 

 also as large shrubs. These are further 

 grouped into about 222 genera and 69 

 plant families. Of the total, about 150 

 species belong to the single, highly var- 

 iable group, or genus, of hawthorns 

 ( Crataegus) , in which numerous other 

 minor forms (including many shrubs) 

 have been proposed as separate species. 

 About 110 other native tree species are 



tropical or subtropical trees known in 

 the United States only from Florida. 

 Thus, without the hawthorns and the 

 trees confined to Florida, there are 

 about 585 tree species native in the 

 United States. In addition, 90 or more 

 foreign tree species widely planted 

 have escaped from cultivation, and 

 have become naturalized, so that they 

 may be considered properly as at home 

 here. More than a third of these exot- 

 ics are tropical trees limited to Florida. 

 Many other tree species from foreign 

 lands have been introduced as orna- 

 mental, shade, and fruit trees. 



Botanists have named and distin- 

 guished also numerous varieties and 

 more than 85 natural hybrids and ap- 

 parent hybrids among the native trees, 

 including more than 60 hybrid oaks 

 (Quercus). However, foresters distin- 

 guish only a few botanical varieties, or 

 minor variations, by name, although 

 they do recognize unnamed geographic 

 races. Aside from the hawthorns, the 

 largest groups, or genera, of native 

 trees are the oaks, with 57 species; 

 willows (Salix), with 33 species; and 

 pines (Pinus), with 34 species. 



Nearly three-tenths of the 585 native 

 tree species ( excluding hawthorns and 

 the tropical trees of Florida), or 165 

 species, have been selected and in- 

 cluded here primarily for the commer- 

 cial importance of their woods or other 

 products, although a few are more im- 

 portant for other values in forestry. 

 These are grouped in 51 genera, the 

 largest groups being the oaks (Quer- 



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