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 

 mixed plantation of deciduous-leaved trees in which are found some of the 

 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 tha Arboretum. It is believed that there are now 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 Larix 



Ginkgo Libocedrus **""" 



Taxaceae Picea. 



Cephalotaxus Pinus 



Taxus Pseudolarix 



Torreya Pseudotsuga 



Pinaceae Sciadopitys 



Abies Taxodium 



Cedrus Thu J a * 



Chamaecyparis Tsuga 

 Cryptomeria Gnetaceae 



Cupressus Ephedra 



ANGIOSPERMAE 

 MONOCOTYLEDONEAE 



Gramineae Liliaceae 



Arundinaria Smilax 



Phyllostachys Yucca 

 Sasa 



DICOTYLEDONEAE 



Salicaceae Myricaceae 



Populus Comptonia 



Salix Myrica 



