ARE OUR RASPBERRIES DERIVED FROM 
AMERICAN OR EUROPEAN SPECIES? 
Geo. M. 
DARROW 
Bureau of Plant Industry, U. S. Department of Agriculture 
T HAS been the common supposition 
of pomologists that most of our 
cultivated red raspberries are de- 
rived from American species. Va- 
rieties from the European species have 
been considered very susceptible to win- 
ter injury while those from the Amer- 
ican species have been considered very 
hardy. Because varieties of red rasp- 
berries commonly grown in this coun- 
try have been moderately hardy they 
were, therefore, thought to be derived 
from the American species. 
A brief review of the points of dif- 
ference between the two species of red 
raspberries which are the parents of our 
cultivated varieties will show how er- 
roneous this view is. 
Rydberg" gives the following distine- 
tions between the European and Amer- 
ican species : 
EUROPEAN SPECIES 
Rubus idacus 
(1) Plant not at all glandular—hispid.... 
(2) Stems finely tomentose when young.. 
(3) Peduncles and sepals tomentose 
Card’ states that Rubus idaeus “is 
stouter and less free in its habit of 
growth, the leaves are a little whiter 
beneath, thicker, and generally some- 
what wrinkled and the canes are lighi 
colored, bearing purple prickles in some 
varieties. The prickles on the finer 
parts are firmer, recurved, and less 
numerous.” He also states R. idaeus 
bears more or less throughout the sum- 
mer and that it is susceptible to winter 
injury. 
*North America Flora, Vol. 22, Part 5. 
*F. W. Card, “Bush Fruits,” p. 167. 
*“Species Ruborum,” W. C. Focke, p. 209 
Foche® makes but one species of both, 
classing FR. strigosus as a variety of 
R. idaeus. His distinctions between the 
two, however, are similar to those of 
Rydberg, but he emphasizes the fact 
that while the upper part of the ma- 
ture plants of R. strigosus is densely, 
rarely sparsely bristly, the upper part 
of R. idaeus is without bristles. 
An examination of Rubus idacus 
grown in this country under garden 
conditions show that these distinctions 
are apparently correct. As Rydberg 
states, the plants are not glandular- 
hispid, the stems. peduncles,» and 
sepals are tomentose, the fruit is dark 
red and thimble shaped. As Card 
states, the canes are stouter, and less 
free in habit of growth. The prickles 
are firm, recurved, and less numerous 
than the bristles of FR. strigosus. Some 
AMERICAN SPECIES 
Rubus strigosus 
Plant glandular—hispid, especially in the 
inflorescence. 
Stems not tomentose. 
Peduncles not tomentose, 
tomentose. 
Fruit light-red. 
Fruit hemispherical. 
sepals slightly 
of the plants bear in the autumn, 
though it may be that in the more 
humid climate of northern Europe they 
would bear still more in autumn. They 
are more susceptible also to winter in- 
jury than R. strigosus. As Focke 
states, no bristles appear on the upper 
part of the mature plants of R. idacus. 
Examinations of the cultivated va- 
rieties of raspberries known to have 
been introduced from Europe confirm 
this. (See Fig. 20.) Their. fruit is of 
