PREFACE. 



Many years ago, when I first realized the difficulty of obtaining any true kno-vvl- 

 edge of the trees of this country, I formed the plan of -writing a Silva -which should 

 contain an account of all the species that gro-w spontaneously in the forests of North 

 America, The books which had been -written on this svibject related only to the trees 

 of comparatively limited regions, and therefore presented no general or systematic 

 view of the composition of our forests. Such Avorks as existed were long out of 

 date, too, and included none of the information collected by recent explorers and 

 observers, and no account Avhatever of the trees discovered in late years west of the 

 Mississippi River. Many of our trees have never been fully described. All that can 

 be learned about them from books is contained in a few words of purely technical 

 description of little value to the general reader ; and these descriptions are widely 

 scattered in American and foreign publications, to be found only in a fcAv special 

 libraries beyond the reach of the general reader. The difficulty of studying our 

 trees has been increased, too, by the fact that many of them have been named by 

 different botanists in different countries without proper regard to names previously 

 bestowxd upon them, so that such a mass of synonyms has been heaped upon some 

 of the species that it is extremely difficult to determine the names which they 

 should rightly bear. Books, however, are only guides towards obtaining a knowl- 

 edge of trees. To be really understood, they must be studied in the forest; and 

 therefore, since the plan of writing this Silva was formed, I have examined the 

 trees of America growing in their native homes from Canada to the banks of the 

 Rio Grande and the mountains of Arizona, and from British Columbia to the islands 

 of southern Florida. I have -watched many of them in the gardens of this coun- 

 try and in those of Europe, and there are now hardly half a dozen of the trees 

 which Avill be described in this w^ork which I have not seen in a living state. 



It may be useful to glance at the books which have been specially devoted to 

 the trees of North America. The earliest is the Arbustum Americanum, which was //^ 

 written by Humphrey Marshall, and published in Philadelphia in 1785. Marshall 

 was a Pennsylvania farmer and a kinsman of John Bartram, who bore the title of 

 king's botanist and enjoyed the friendship and correspondence of many European 

 men of science. Bartram established the first Botanical Garden in America. Marshall 

 followed his example, and collected several American trees on his farm in Chester 

 County. Here, as w^ell as during his numerous journeys, he acquired much infor- 

 mation Avith regard to the trees of the eastern part of the country, Avhich he 



