COMPLIMENTARY 
NEW SERIES VOL. IX 
NO. 17 
ARNOLD ARBORETUM 
HARVARD UNIVERSITY 
POPULAR INFORMATION 
JAMAICA PLAIN. MASS. DECEMBER I. 1923 
Conifers. The Arboretum collection of these plants has the reputa¬ 
tion of being the largest and most complete in the United States, and 
no effort has been spared during the last fifty years to make it so. It 
shows perhaps fairly well which of these plants can be grown with more 
or less success in New England, but compared with what such a collec¬ 
tion might be made in a climate really suited to these plants the Ar¬ 
boretum conifers have little to boast of. Of the twenty-eight genera 
of these plants which are now recognized fifteen only are represented 
in the Arboretum collection, with about one hundred and eight species 
and a large number of varieties. In the genera which cannot be grown 
in New England are some of the noblest and most interesting trees in 
the world, like the Sequoias, the Araucarias, the Taiwania, the Fitz- 
roya, the most valuable of the cone-bearing trees of South America, 
the different species of Agathis, sometimes called Dammara or Damma 
Pines, and the Chinese Keteleerias. The Arboretum collection contains 
all the species of northeastern North America, a few European, Cau¬ 
casian and central Asiatic species, the species of northeastern Asia, 
many of those of western China and of Japan, and of the northern Rocky 
Mountain region of North America. No conifer which grows south of 
the equator can be grown in New England. Mexico, the home of 
many conifers, especially of the genus Pinus, has contributed only one 
Pine-tree to the Arboretum collection. None of the important Pine- 
trees of the coast region of the southern United States are hardy at 
the north; and of the conifers of the Pacific States which do not range 
eastward into the Rocky Mountain region only Pinus ponderosa var. 
Jeffreyi is really successful here. The Incense Cedar {Libocedrus decur- 
rens) has, however, grown fairly well in an exceptionally well sheltered 
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