BULLETIN NO. 41. 
The Horsechestnut ( Aesculus Hippocastanum) growing naturally in a 
restricted area has the power of flourishing and reproducing itself in 
regions with climates as unlike as those of eastern New England and 
western Scotland. The home of this tree among the mountains of 
northern Greece is of such limited extent that, although the Horse- 
chestnut has been cultivated in Europe for more than three centuries,, 
it is only in comparatively recent years that the wild tree has been 
discovered. The Grecian Horsechestnut is one of the noblest of the 
exotic trees cultivated in the United States, but for the development 
of its greatest beauty it requires deep, rich, moist soil and abundant 
space for the spread of its branches. Few other trees suffer more 
from smoke, dust, and the other unnatural conditions of city life. There 
are a number of forms in cultivation but none of them equal the typical 
tree in beauty. One of the best known of these abnormal forms is the 
variety with double flowers (var. Baumannii, or jlore pleno). This form 
flowers later than the single-flowered tree and the flowers last a long 
time in good condition. There are varieties with erect branches (var. 
pyramidalis) and with erect and spreading branches forming a round- 
topped tree (var. umbraculifera ) ; and there are varieties with variously 
incised leaflets (var. incisa and var. laciniata ), and with leaves blotched 
with yellow (var. variegata) , but these are all horticultural curiosities 
and of no interest to the general planter. 
The so-called red-flowered Horsechestnut, which appeared in Europe 
many years ago, although its origin is not entirely clear, is probably a 
hybrid of the common Horsechestnut with the red-flowered A. Pavia of 
the southeastern United States. The right name of this tree is A. car- 
nea, although it is often found in nurseries under the name of A. rub- 
icunda. It has the general habit and appearance of the common 
Horsechestnut, but it is a smaller tree and blooms later, and the flow- 
ers on different individuals vary from red to pale rose color. The 
handsomest form (var. Briotii) has deep red flowers and is one of the 
most ornamental of the arborescent Horsechestnuts. The Japanese 
Horsechestnut {A. turbinata) is rather closely related to the Grecian 
tree and resembles it in general appearance, although the flowers are 
less showy. In its native country this is a large and handsome tree, 
and it promises to be a valuable ornamental tree here. The largest 
specimen in the United States is in Rochester, New York, where the 
Japanese Horsechestnut has flowered and produced large crops of seeds 
for several years. The Himalayan Horsechestnut, the species from 
central China discovered by Wilson, and the California species are not 
hardy here, and the north China Horsechestnut is not yet established in 
the Arboretum. 
Southeastern North America is the real home of the Horsechestnuts, 
judging by the multiplication of species in that part of the world where 
a number of interesting and valuable new forms have recently been 
discovered. The earliest of the American species to flower is the so- 
called Ohio Buckeye, A. glabra, which has now been in bloom for ten 
days. This is a small tree with pale yellow flowers, fruit like that of 
the Grecian tree covered with prickles and dark bark exfoliating in 
thin flakes. There is a tree of the Ohio Buckeye in the Horsechestnut 
Group on the Meadow Road, but the largest specimen in the Arbore- 
tum is on the left-hand side of the South Street entrance. A form of 
this tree with usually seven instead of five leaflets (var. Buckleyi) is 
