Complimentary 
NEW SERIES VOL. IV 
NO. 8 
ARNOLD ARBORETUM 
HARVARD UNIVERSITY 
BULLETIN 
OF 
POPULAR INFORMATION 
JAMAICA PLAIN, MASS. JUNE 12. 1918 
Philadelphus. Few plants give greater beauty to northern gardens 
than the Syringas or Mock Oranges. These are the unfortunate pop- 
ular names of the different species of Philadelphus, for Syringa is the 
botanical name of the Lilac, and Mock Orange is the popular name of 
Prunus caroliniana^ a southern evergreen Cherry which is much planted 
in the southern states as an ornamental tree and in making hedges. 
The species of Philadelphus grow naturally in southeastern Europe and 
the Caucasus, in the United States on the southern Appalachian Moun- 
tains, in western Texas, on the southern Rocky Mountains, and in the 
northwestern states, in Japan, Korea, northern and western China, and 
on the Himalayas. In the last twenty years much attention has been 
paid to the introduction of new species; artificial and natural hyorids, 
too, have increased the number of these plants, and there are now 
growing in the Arboretum some thirty species and a number of varie- 
ties and hybrids. The flowering period of the Syringas extends through 
six or seven weeks and, with few exceptions, none of them begin to 
bloom until that of most Lilacs and of the Bush Honeysuckles has 
passed. With its development in recent years Philadelphus has become 
one of the important groups of garden shrubs to be ranked with the 
Lilacs, Bush Honeysuckles, Viburnums and Azaleas. The species and 
hybrids of Philadelphus are nearly all hardy in Massachusetts but the 
white and usually fragrant flowers are their only attraction. They are 
not particularly interesting in habit; the foliage is dull; the leaves fall 
without change of color, and the fruit, which is a dry capsule, is 
smaller and not more attractive than that of the Lilac. All the Syr- 
ingas flower freely nearly every year; they need rich, well-drained soil, 
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