402 



even more slowly. It was not until the 

 middle of the eighteenth century that 

 this aspect had become sufficiently 

 popular to interest men of means to 

 become the patrons of horticultural 

 science. Then the world was searched 

 for new and rare species and the pa- 

 trons financed the publication of some 

 magnificently illustrated volumes. And 

 so, as the functions of botanical gar- 

 dens and arboretums were gradually 

 multiplied, the scientific and educa- 

 tional aspects became more and more 

 important. 



From the writings of several men we 

 have taken ideas on how arboretums 

 should serve the public: 



To grow a complete collection of the 

 best hardy plants so that the public 

 may become acquainted with their 

 names and characteristics. 



To test and introduce new plants 

 and varieties in order to increase the 

 productivity, economic importance, 

 and beauty of the region. 



To maintain research; to provide a 

 laboratory for the students of botany, 

 horticulture, forestry, as well as nature 

 study; and to provide collections of 

 tree species for scientific breeding. 



To serve as a laboratory adjunct to 

 the schools, garden clubs, and other or- 

 ganizations; to disseminate knowledge 

 of plants and the culture of plants 

 through lectures and publications ; and 

 to provide recreational stimulus to the 

 public. 



To conserve the native plant life of 

 the region. 



To train gardeners. 



To cooperate with related institu- 

 tions and agencies for the extension of 

 knowledge. 



No single arboretum can necessarily 

 fulfill all of those functions; the func- 

 tions of an arboretum depend on the 

 available area and funds and some- 

 times on the conditions under which 

 the funds are granted. 



An arboretum should never become 

 a public park, in the sense of a recrea- 

 tional or picnic area where people can 

 wander at will over the land. An 

 arboretum should be laid out with 



Yearbook^ of Agriculture 1949 



adequate footpaths leading to speci- 

 men plants, and visitors should be re- 

 quired to stay on the paths extensive 

 trampling results in packing of the 

 soil and finally to degeneration of the 

 trees themselves. Trees and shrubs 

 should be clearly labeled with their 

 name and their native habitat. Addi- 

 tional interesting information may be 

 given for many trees, such as the 

 offspring of historic trees or the special 

 uses of some trees. 



Arboretums are of great importance 

 not only to the landscape practitioner 

 but also to the forester. Most of the 

 forest schools and forest research insti- 

 tutions of Europe have arboretums of 

 timber trees and, in the United States, 

 some of the forest schools and forest 

 experiment stations also maintain such 

 collections. The arboretum of the Cali- 

 fornia Forest and Range Experiment 

 Station, near Placerville, Calif., is one 

 of the largest collections of pines in 

 the world. It was established in 1925 

 as a breeding arboretum for the im- 

 provement of this group of timber 

 trees. It is a good example of a highly 

 specialized arboretum containing spe- 

 cies of pine from all over the world. 



At present, the forest-tree breeding 

 work in the eastern United States is 

 being carried on at Philadelphia, a 

 community that is particularly rich in 

 blooming specimens of many tree spe- 

 cies because of its favorable climate 

 and because of the great interest in 

 botany of some of its prominent early 

 settlers. Men like Bartram made Phila- 

 delphia a center of botanical studies 

 even before the Revolution, and the 

 continued interest of the owners of 

 estates has given us a heritage of na- 

 tive and exotic tree species that now 

 makes hybridization work possible. 



W. H. LARRIMER, a forester, has 

 worked in the Department of Agricul- 

 ture for 35 years, and has done field 

 work in every State. 



ERNST J. SGHREINER has done re- 

 search in tree breeding since his 

 graduation in 1924 from Syracuse Uni- 

 versity. 



