Complimentary 
NEW SERIES VOL. VI 
NO. 7 
ARNOLD ARBORETUM 
HARVARD UNIVERSITY 
BULLETIN 
OF 
POPULAR INFORMATION 
JAMAICA PLAIN, MASS. JUNE 4. 1920 
Japanese Azaleas. The flora of Japan contains many species of 
Azaleas, and in early spring their brilliant flowers enliven innumer- 
able hillsides. Many species and varieties are favorite garden 
plants in Japan, and Japanese gardens owe much to these plants. In 
distribution the Azaleas of Japan are generally southern, and only a 
few species are found in the northern part of the empire. All of the 
species will probably flourish in the southern United States; and many 
of them will succeed as far north as Long Island and possibly in New- 
port, Rhode Island. Of the sixteen Japanese species three are well 
established and hardy in the Arboretum; a northern species. Rhododen- 
dron (all Azaleas are now called Rhododendrons by botanists) Albrechtii- 
related to our Rhodora but with red flowers, judging by the climate 
of the region in which it grows, should also be hardy here. This hand- 
some plant, however, which was first raised at the Arboretum twenty- 
five years ago, has not been a success here. Another northern species. 
Rhododendron Tschonoskii, with the smallest flowers of any Azalea, 
is an old inhabitant of the Arboretum but is without value as 
an ornament of gardens. Two beautiful Azaleas from the mountain 
forests of central Hondo, Rhododendron Rehderianum and R. penta- 
phytlum, have not yet been sufficiently tested in the gardens of this 
country; they may be expected to be able to bear the cold of Massa- 
chusetts winters, but appear difficult to establish. Another Japanese 
Azalea, R. mucronatum, generally known as “Azalea ledifolia” or 
as “Azalea indica alba,” has been seen in American gardens for the 
last eighty years. It is very often found in the old gardens of the 
southern states; it is hardy and often cultivated on Long Island, and 
occasionally lives for many years in sheltered positions in eastern Mas- 
sachusetts. The three Japanese species, which have proved themselves. 
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