Complimentary 
NEW SERIES VOL. VI 
NO. 4 
ARNOLD ARBORETUM 
HARVARD UNIVERSITY 
BULLETIN 
OF 
POPULAR INFORMATION 
JAMAICA PLAIN, MASS. 
MAY 19, 1920 
Pear Trees. The Arboretum collection of the wild types of Pear-trees, 
especially those of eastern Asia, is probably now the largest to be 
found in any arboretum, and as many of the species now flower and 
produce large crops of fruit this collection is of particular interest to 
pomologists who hope to find among these trees a stock resistant to 
blight on which to graft their orchard Pear-trees with edible fruit. 
The earliest of the Asiatic Pear-trees this year, Pyrus ussuriensis, 
began to flower two weeks ago. This tree, which is common in north- 
ern China, Korea and Manchuria and the only species which has a foot- 
hold in Japan where it has recently been discovered, inhabits more 
northern and colder regions than any other Pear-tree. If any Pear- 
tree proves hardy therefore in the northern interior part of this conti- 
nent it should be this species; and if it proves resistant to blight it 
should yield the hardiest of all Pear-stocks. No other species attains 
such a large size as is shown by the photograph made in 1919 by Wil- 
son in Korea of a tree which was sixty feet high, with a tall trunk 
seven feet round and a head of spreading branches seventy-five feet 
across. The flowers are not as large as those of some of the other 
species, but as a flowering tree P. ussuriensis is one of the most beau- 
tiful of all Pear-trees for the flower-buds and the opening flowers are 
deeply tinged with rose-color. The fruit is subglobose, green, hard and 
one-half to three-quarters of an inch in diameter and, like that of most 
wild Pear-trees, is of no comestible value. Among other Pear-trees this 
northern species, as a young tree at least, can be easily recognized by 
its smooth pale bark. Pyrus ovoidea, which was introduced into west- 
ern gardens from northern China, and is an old inhabitant at the Arb- 
oretum, is now considered by botanists a variety of the Korean Pear- 
tree (var. ovoidea). It blooms two weeks later than the more northern 
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