S" v 
Complimentary 
NEW SERIES VOL. V 
NO. 15 
ARNOLD ARBORETUM 
HARVARD UNIVERSITY 
BULLETIN 
OF 
POPULAR INFORMATION 
JAMAICA PLAIN, MASS. 
OCTOBER 24, 1919 
Pseudolarix amabilis. It is an interesting fact that the monotypic 
genera of conifers, that is, the genera of a single species, of the 
northern hemisphere, are confined to eastern Asia. There are seven 
of these genera: Glyptostrobus, Taiwania, Fokienia, Cryptomeria, 
Thujopsis, Sciadopitys, and Pseudolarix. Unfortunately several of 
these trees are not hardy in the northern United States. Glyptostro¬ 
bus, Taiwania and Fokienia grow in warm regions; they might succeed 
in some parts of Florida and Louisiana, but California will probably 
prove our best region for them. Cryptomeria can just be kept alive 
in the Arboretum, but fairly healthy specimens can occasionally be seen 
in gardens on Long Island and southward in the eastern states. An 
abnormal form of this tree (var. elegans) appears to be rather hardier 
than the type and to be more often cultivated in the eastern states. 
There is a small tree of Thujopsis in Wareham, on Cape Cod, but this 
beautiful Japanese tree has not proved to be hardy in the Arboretum. 
A variety (var. Hondai) from the extreme northern part of Hondo may 
prove hardier than the type. Seedlings of this northern variety have 
been growing in the Arboretum since 1915. Sciadopitys, the Japanese 
“Umbrella Pine,” although the leaves are sometimes badly burned in 
severe winters, is hardy in Massachusetts. It is an interesting and 
handsome tree, forming while young a dense pyramid. It grows so 
slowly, however, that it will not be popular with those planters with 
whom rapidity of growth is the chief merit in a tree. For the north¬ 
ern states and for general cultivation the most valuable of the mono¬ 
typic Asiatic conifers certainly is the Chinese Golden Larch Pseudo- 
57 
