1834 TREES 



per cent, which percentage surpasses by far that of any 

 other country in the temperate regions. 



Trees belong to many different natural orders, but of 

 the orders of monocotyledonous plants only a few con- 

 tain trees and none of them is hardy north. None of the 

 larger orders contains trees only, but there are some 

 which consist exclusively of woody plants and include a 

 large proportion of trees, as Coniferse, Cupuliferte, 

 Salicacefe, Juglandacese, Magnoliaceae, Sapindaceae, 

 ElseagnaceiB, Ulmaceie, Hamamelidacece, Lauracese, 

 Anacardiacefe, Ebenacero, Styracaceae and others. 



The uses of trees are manifold, and a country from 

 which the forests have been destroyed becomes almost 

 uninhabitable and worthless to mankind. The forests 

 furnish wood and timber, exercise beneficial influences 

 on the climate, act as regulators of the waterflow, pre- 



self , the trees and shrubs do not need his perpetual 

 care and usually grow without bis aid and interference. 

 To the landscape gardener a thorough knowledge of 

 trees is absolutely essential. He ought to know the or- 

 namental properties of the trees, their rate and mode of 

 growth, their peculiarities in regard to soil, situation 

 and climate. As the trees are, after the surface of the 

 ground, the most permanent element of the landscape, 

 they ought to be planted with careful deliberation as to 

 the intended artistic effect and their fitness to the soil 

 and climatic conditions, for mistakes in planting of 

 trees are afterwards not easily corrected and rarely 

 without injury to the original artistic design. The 

 available number of trees from which selection may be 

 made is large. There are in American and European 

 nd gardens more than COO species in cultiva- 



A group of old I 



maples, with Irregular i 



I broken heads. 



vent erosion and also the removal of soil by the wind. 

 Besides furnishing wood and timber, many trees yield 

 other products of great economic importance, especially 

 the numerous kinds bearing fruits. The esthetic value 

 also of the tree must not be underrated, though it can- 

 not be counted in money. 



The science of trees and shrubs is dendrology. The 

 art of growing trees is arboriculture, of which sylvi- 

 culture is a branch and deals with the rearing and main- 

 taining of forests and the producing of wood crops. 

 Orchard culture is a branch of arboriculture or of hor- 

 ticulture and deals with the cultivation of fruit trees; 

 it is usually included under pomology, which comprises 

 both the science and practice of fruit-growing. As or- 

 namental subjects, trees are more permanent, easier of 

 cultivation and cheaper in the long run than herbs. It 

 is curious to note how little attention the average gar- 

 dener who has the care of a park or garden gives 

 to the most prominent feature of his domain. He 

 usually knows fairly well the greenhouse plants and 

 his herbaceous perennials, which cost most in time 

 and money, but the trees and shrubs he often hardly 

 deigns to look at. This is apparently due to the fact 

 that after being once planted, and often not by him- 



tion which are hardy in the northern and middle states. 

 About 240 of them are American, almost 200 from eastern 

 Asia, about 100 from Europe and 70 from western and 

 central Asia. About 40 natural orders are represented, 

 of which the most important are the Coniferae, Cupu- 

 liferse, Salicaceae, RosaceiP, Leguminosse, Juglandacese, 

 Sapindacese, Urticaceee, Magnoliaceaj and Oleacea). The 

 number of all the cultivated varieties and garden forms 

 is, of course, considerably larger than that of the botani- 

 cal species and may be estimated at about 3,000. Com- 

 paratively few horticultural varieties are found in 



the 



prev 



ling character of the masses 



i of 



The fundamental purposes of trees in landscape 

 gardening are to furnish the great masses of foliage 

 which frame and (^vide and partly constitute the views 

 and landscape pictures, to emphasize the elevations of 

 the ground, to vary the sky-line, to screen or block out 

 unsightly objects, to enhance the beauty of buildings. 



