68 
All the species with many varieties are in the Arboretum, and all 
do well here with the exception of the north China T. orientalis 
which probably needs a drier climate, for it is the only conifer which 
really grows well on the plains of western Kansas. The Red Cedar of 
the northwest coast ( Thuya plicata or gigantea) is one of the great 
trees of the world, and in the Arboretum has grown to be one of the 
handsomest conifers in the collection. 
Chamaecyparis, which differs from Cupressus chiefly in the fruit 
which matures at the end of the first season, is the name of the White 
Cedar. The genus is confined to the coast regions of eastern and west¬ 
ern North America, to Japan and Formosa. The two Japanese spe¬ 
cies often called Retinosporas, with many abnormal forms, are common 
in gardens and old inhabitants of the Arboretum. The eastern Amer¬ 
ican species, Chamaecyparis thyoides , although a common inhabitant 
of Massachusetts swamps, has grown slowly in the Arboretum and has 
occasionally been partly killed in severe winters. The handsomest and the 
largest of the genus, and one of the noblest of North American trees, 
Chamaecyparis Lawsoniana , the Lawson Cypress as it is often called, 
can only drag out a miserable existence here, and the beautiful Alaska 
Cedar, Chamaecyparis nootkatensis , is not hardy here. 
Tsuga, the name of the Hemlock, is another small genus with species 
in eastern and western North America, Japan, western China and the 
Himalayas. The western American species exist here, but will prob¬ 
ably never become large trees. The mountain Hemlock of Japan (T. 
diversifolia ) is hardy and healthy, but it grows slowly and is not as 
handsome as our native species. The handsome but less hardy T. Sie- 
boldii, a more southern tree, lives in sheltered positions but does not 
seem suited for general planting in Massachusetts. The Chinese spe¬ 
cies ( Tsuga chinensis) has lived for several years in the Arboretum, 
although it was a good deal injured in the winter of 1917-18. The 
handsomest of the Hemlocks which can be grown in Massachusetts and 
now one of the most beautiful trees in the Arboretum is a native of 
the southern Appalachian Mountains, Tsuga caroliniana. 
Pseudotsuga. Of the three species of this genus only the Rocky 
Mountain form of Pseudotsuga taxifolia is hardy here. It has been 
growing in Massachusetts since 1863, and up to this time has proved 
one of the hardiest, handsomest and most rapid growing conifers which 
has been brought into this part of the country. 
Juniperus. This is one of the largest and most widely distributed 
genera of conifers, for Junipers are found in all temperate and elevated 
parts of the Northern Hemisphere; they flourish in arid semi-desert 
regions in the interior of continents, and extend into the tropics. Some 
species are large and valuable trees and others are prostrate shrubs, 
the same species being sometimes a tree and sometimes a shrub. 
Massachusetts is too cold and wet for most Junipers, and only a small 
number of species with a number of varieties have been successfully 
grown in the Arboretum. The mild winter and the wet summer and 
autumn have helped this collection and the Arboretum Junipers have 
not before been in as good condition as they are now. 
These Bulletins will now be discontinued until the spring of next year. 
