^srT&T ’T'TjT' 
NO. 10 
NEW SERIES VOL. V 
ARNOLD ARBORETUM 
HARVARD UNIVERSITY 
BULLETIN 
OF 
POPULAR INFORMATION 
JAMAICA PLAIN, MASS. JUNE 24, 1919 
Rosa rugosa, which is an old inhabitant of gardens, is a native of 
the coast sand-dunes of northeastern Asia from northern Japan to 
Kamtchatka. The thick dark green leaves seem able to resist the 
attacks of insects and the diseases which often discolor the leaves of 
many Roses. The flowers of the typical wild plant from Japan are 
red, but there are varieties with pure white and with clear pink flow¬ 
ers. The Kamtchatka plant, which is less ornamental than the Japan¬ 
ese plant, with smaller and thinner leaflets and smaller flowers is 
treated by many botanists as a species distinct from the Japanese plant 
and called by them Rosa kamtschatica. There is a double-flowered 
form of this continental plant in the Arboretum collection which pro¬ 
duces flowers which are as ugly as it is possible that a Rose flower can 
become. No other Rose is hardier than Rosa rugosa, and left to itself 
it spreads into great thickets. No shrub is better suited to grow 
in exposed positions on the New England coast; it grows equally well 
in the rich soil of the garden, and no other Rose is so valuable in this 
climate for making low hedges. Valuable as the Japanese Rosa rugosa 
has proved itself as a garden plant its greatest value is in its ability 
to transmit its hardiness, handsome foliage and large flowers to its 
hybrid offspring. Among these are already several beautiful garden 
plants which suggest that the plant breeder who wishes to produce 
new races of Roses able to grow and flower successfully in the north¬ 
ern states must combine Rosa rugosa and its hybrids with other hardy 
Roses. Rose breeders are singularly reticent about the plants they 
have used in their work, and there appear to be no printed records of 
FEB HjB2$ 
37 
