Complimentary 
NEW SERIES VOL. VI 
NO. 12 
ARNOLD ARBORETUM 
HARVARD UNIVERSITY 
BULLETIN 
OF 
POPULAR INFORMATION 
JAMAICA PLAIN, MASS. JULY 9. 1920 
Pterocarya is a genus of trees of the Walnut Family, differing from 
the Walnuts and Hickories in its small winged nut arranged on a long 
pendulous raceme and smooth bark. It has the long pinnate leaves of 
the other members of its Family and pith like that of the Walnuts, in 
thin plates, not solid like the pith in branches of Hickory-trees. The 
genus is a small one and grows naturally only in the Caucasus, central 
and southern China and in Japan. The Caucasian species, Pterocarya 
fraxinifolia, was the first of these trees planted in western Europe 
and the United States, it having been brought to Europe from Persia 
in 1782 by the French traveller Michaux whose name is a household 
word with students of the American flora. This tree appears to have 
been first planted in the United States at the beginning of the nine- 
teenth century at the Woodlands in West Philadelphia, the famous Ham- 
ilton garden where it is believed that the Lombardy Poplar was first 
planted in the United States. Three of these trees were growing at 
Woodlands, at that time a cemetery, thirty years ago. They had not 
grown to a large size but were in good health; it is reported that 
these trees have now disappeared. There in an old specimen of this 
tree in the Harvard Botanic Garden at Cambridge which possibly was 
planted when this garden was laid out more than a century ago. This 
tree is hardy and is perhaps the oldest and largest specimen in the 
United States, but it is not a handsome tree and has never looked as 
if its surroundings agreed with it. The Caucasian Pterocarya has been 
a difficult tree to establish in the Arboretum, and there is only a young 
specimen here which does not give much promise of becoming a tree. 
The climate of England, France and Italy suits this tree much better 
than that of the northeastern United States; and several specimens 
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