1922] SARGENT, FIRST FIFTY YEARS OF THE ARNOLD ARBORETUM 



137 



of Pear-trees, and the collection of Poplars and Alders; below the top 

 of the hill and near the western boundary of the Arboretum is a large 



found some of the 



mixed plantation of deciduous-leaved trees in which 

 rarest and most interesting species in the whole collection, for this exposed 

 hilltop has proved favorable to the growth of several trees which have not 

 flourished in the Arboretum at lower levels. The land between South 

 Street and the railroad will be used for new and enlarged collections of 

 Poplars and Willows, and the addition between Centre and Walter will be 

 chiefly planted with trees which require deep soil and good drainage to 

 enable them to grow to a large size and live to old age. 



The regions represented by the living collections are the cool temperate 

 and colder parts of North America, Europe and Asia, including the 

 higher altitudes of the Himalayas and other more southern mountains. 

 No plants from the southern hemisphere, not even from the high Andes, 

 southern Chile or the higher mountains of New Zealand have proved 



hardy in tli3 Arboretum. It is believed that there are 



growing in the 



Arboretum between five and six thousand species and varieties of trees 

 and shrubs which belong to the following Families and Genera: 



GYMNOSPERMAE 



Ginkgoaceae 



Ginkgo 



Taxaceae 



Cephalotaxus 



Taxus 



Torreya 



Pinaceae 



Abies 



Cedrus 



Chamaecyparis 



Cryptomeria 



Cupressus 



Larix 



Libocedrus 



Picea 



Pinus 



Pseudolarix 



Pseudotsuga 



Sciadopitys 



Taxodium 



Thuja 



Tsuga 



Gnetaceae 



Ephedra 



Gramineae 



Arundinaria 

 Phyllostachys 



Sasa 



Salicaceae 



Populus 

 Salix 



ANGIOSPERMAE 

 MONOCOTYLEDONEAE 



Liliaceae 



Smilax 

 Yucca 



DICOTYLEDONEAE 



Myricaceae 



Comptonia 

 Myrica 



