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eral name is S. rubens, although under this general name are several 
different trees of the same hybrid parentage to which different names 
have been given. 
It is not known here if trees of the two sexes of this hybrid exist 
in the United States, and nothing is known of the distribution in dif- 
ferent parts of the country of the different forms of the hybrid; and 
if any reader of this Bulletin has paid attention to the Tree Willows 
naturalized in the United States, the Arboretum will be glad to hear 
from him. 
Staphyleas. A reader of these Bulletins has asked us to say some- 
thing about Staphyleas, or Bladder Nuts as these plants are popularly 
called. Staphylea is a genus of shrubs with opposite, trifoliate or pin- 
nate, deciduous leaves and terminal clusters of small white or pinkish 
flowers, and much inflated, membranaceous, pod-like fruits which vary 
in length on the different species from one to four inches. There are 
several species and one hydrid, and a species occurs in each of the 
chief botanical regions of the northern hemisphere. All these plants, 
with the exception of the Himalayan S. Emodi, are in the Arboretum, 
but in the Shrub Collection where the winter conditions are more severe 
than in any other parts of the Arboretum they are often killed nearly 
to the ground by cold and give little satisfaction. The plants on 
Azalea and Hickory Paths do better, and probably all the species would 
flower and ripen their fruit here if the right place could be found for 
them. 
The species of eastern North America, S. trifolia, grows from the 
Province of Quebec westward to Nebraska and southward to Oklahoma 
and Georgia. It is occasionally seen in old gardens in this country 
and in England it has been cultivated for two hundred years. As a 
garden plant, however, it has little to recommend it. The northern 
California species, S. Bolanderi, exists on Hickory Path but has not 
yet flowered in the Arboretum. Staphylea holocarpa has pinkish flow- 
ers which appear before the leaves, and is a small tree sometimes 
twenty feet high discovered by Wilson in central China and considered 
by him one of the handsomest flowering trees which he saw in China. 
This plant can be seen on the upper side of Azalea Path where the 
ends of the branches are often killed by cold; it has not yet flowered 
in the Arboretum. The species already named have leaves with three 
leaflets: the following usually have leaves with from five to seven 
leaflets. S. pinnata, which is widely distributed through Europe to 
western Asia, is a tree-like shrub and sometimes flowers here but has 
little value as a garden plant in this climate. The Caucasian S. col- 
chica, which differs from S. pinnata in its larger flowers and fruits 
and in the lustrous lower surface of the leaves, is the handsomest of 
the Bladder Nuts and well worth cultivation. Small plants flower freely 
and are often used in England for the winter decoration of conservato- 
ries. A variety of this plant, or a hybrid between it and S. pinnata, 
is S. Coulombieri which appeared many years ago in a French nursery 
and is distinguished by its larger leaves and by the flowers and fruit 
which are intermediate in size between those of its supposed parents. 
The variety Hesaei of S. colchica, distinguished by its pinkish flowers, 
is in the collection but has not yet flowered here. 
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