INTRODUCTION. 3 



Nearly five hundred species of trees grow in the United 

 States,* and there are others that are peculiar to other 

 countries, yet the great mass of wood used in construction 

 comes from but few of them. Dr. Sudworth excludes all but 

 100 species in his "Trees of the United States Important to 

 Forestry," while a Treasury Department Summary f contains 

 the statement that but sixteen kinds of hard wood were quoted 

 in Chicago markets on the first of September in the year 

 nineteen hundred. 



Woods appear to be more numerous than is actually the case, 

 because several names are often applied to a single product. 

 Woods have been brought long distances because the same 

 ones nearer by were not recognized when called by different 

 local names. The longleaf or southern pine (Pinus paluslris} 

 has about thirty common names. Such confusion can only be 

 avoided by regarding the recognized botanical nomenclature. 



Conditions are changing; many woods that were formerly 

 common are now quite scarce while others that have been less 

 familiar must be employed. Information is increasing with 

 regard to valuable properties possessed by species that have 

 been less familiar. 



The botanical name of a plant consists cf two principal 

 terms denoting genus and species. Quercus, for example, is 

 the generic name including all species of oak. Alba, rubra, 

 ar.d others are specific names denoting the said species. 

 Quercus alba and Quercus rubra are completed terms. Genera 

 are not fixed but differ with authorities, so that the abbreviated 

 name of the botanist responsible for the classification adopted 

 is often added, as Quercus alba Linn, and Ulmus fulva Michx. 



A species is a collection of individuals that might well have 

 sprung from some single root. A genus is a collection of related 

 species. Genera are gathered into families. Families and genera 



* Dr. Fernow credits 495 species to the United States (Introduction to U. S. 

 Forestry Bui. 17); Prof. Sargent counting species only and excluding varieties, 

 notes 422 species (Silva of North America). 



f (1900, p. 1081). The statement is also made that the principal timbers of 

 commerce in the United States are the species known popularly as pine, fir, oak, 

 hickory, hemlock, ash, poplar, maple, cypress, spruce, cedar and walnut. 



