170 THE CULTIVATED EVERGREENS 



the very interesting facts connected with the history and par- 

 ticularly with the introduction of the different species into 

 cultivation. In most cases, only the date of the first introduc- 

 tion into cultivation has been given, and these dates concern 

 chiefly the introduction into European gardens. It is to be 

 regretted that very few data are available regarding the intro- 

 duction of plants into American gardens except those of recent 

 date; it would certainly prove to be an interesting and fasci- 

 nating study to trace the historical development of the plant 

 material of our gardens and the various attempts to introduce 

 plants from foreign countries and to bring those of our own 

 rich flora into cultivation. 



NOMENCLATURE, SEQUENCE, AND KEYS 



In the following account of conifers, descriptions are given of 

 only the species and varieties which are actually or are supposed 

 to be in cultivation in North America, but many others are 

 mentioned incidentally. In regard to the botanical names, the 

 International Rules of Botanical Nomenclature are followed 

 and have been strictly applied, but in cases in which the name 

 adopted in the Official Catalogue of Standardized Plant 

 Names (prepared by the American Joint Committee on Horti- 

 cultural Nomenclature), intended as a guide for nurserymen 

 and horticulturists, differs, that name is given as an alternative 

 and may be used instead of the name considered correct under 

 the International Rules by those who prefer to follow that 

 Catalogue. The English names used here are those proposed 

 in that Catalogue. 



As the present treatment is intended chiefly for horticultural 

 purposes, it has not been considered necessary to group the 

 varieties and forms from a strictly botanical point of view and, 

 therefore, no distinction has been made between subspecies, 



