J 
Complimentary 
NEW SERIES VOL. IX NO. 11 
ARNOLD ARBORETUM 
HARVARD UNIVERSITY 
BULLETIN 
OF 
POPULAR INFORMATION 
JAMAICA PLAIN. MASS. 
JUNE 26. 1923 
Philadelphus. Among the shrubs which give beauty to northern gar¬ 
dens in early summer Philadelphus, or as it is popularly called Syringa 
or Mock Orange, is perhaps only surpassed in interest and value by the 
Rose and the Laurel (Kalmia). It is only the abundant and often de¬ 
lightfully fragrant white flowers of the plants of this genus which are 
beautiful; for the fruit is a dry capsule; the habit of the plants is not 
different from that of many other shrubs, and their leaves fall in early 
autumn without having changed their color. The plants are natives of 
eastern and western North America, Japan, China, the Himalayas and 
southeastern Europe. In the Arboretum collection there are some thirty 
species, several distinct varieties of some of the species, and a large 
number of hybrids for in few genera of plants has the hybridizer been 
more successful in producing new and valuable forms. Plants in this 
group are in bloom in the Arboretum during fully six weeks, the earli¬ 
est being a form of Philadelphus Schneckii, named variety Jackii, for 
Mr. J. G. Jack who discovered it in Korea, which in ordinary season 
opens its flower-buds during the last week of May, and the latest, or 
almost the latest, the hybrid P. insignis, which does not flower before 
the middle of July. Among the species which seem best worth a place 
in the garden is the European species P. coronarius, the Mock Orange 
of old gardens, which was cultivated in England before the end of the 
sixteenth century and was probably one of the first shrubs brought to 
America by the English. It is a large and hardy shrub and is chiefly 
valuable for the fragrance of its flowers which are faintly tinged with 
yellow. A number of seminal forms of this plant are cultivated, includ¬ 
ing one with yellow leaves, one with double flowers, and one with nar- 
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