LZ? 
of data on hardiness will of necessity show discrepancies. We 
may summarize the more important reasons for these discrepancies 
as follows: 
I. Possibility of variation between individuals of the same 
species with respect to susceptibility to cold. 
II. Site. Locations in the Garden vary as regards protection 
from cold, soil conditions, and exposure to wind and sun. 
III. Extent to which plants have become established. Speci- 
mens set out within the last year or two may be more susceptible 
to injury than those whose roots are well established in the soil. 
IV. Some individuals may have been predisposed to injury by 
attacks of insects, fungi, from drought, or other external factors. 
V. Other causes for the variation in the physiological condi- 
tion of individuals resulting in predisposition to injury from cold. 
(See paragraph above on “ 
of conditions.”’ ) 
winter injury the result of a complex 
VI. Size of individuals. It is possible that in some cases, 
larger individuals which have grown in a given location for a 
number of years, may be more cold resistant than smaller speci- 
mens—this, too, apart from the fact that their roots are doubtless 
better established in the soil. 
For these reasons the data presented below can not be regarded 
as an absolute criterion of hardiness for any given species. 
Explanation of Symbols Used in List 
The families with indeterminate growth, such as the roses and 
honeysuckles, are of course especially susceptible. Where A has 
been inserted after these or any other species, the meaning is that 
even in spite of the injury the plant looks well, the new growth 
having hidden the dead shoots or shoot tips. It will be noted 
throughout the list that many species are included which were not 
injured. This winter was such a rigorous test that we think it 
advantageous to have at least a partial list of those that passed 
through the ordeal successfully. 
Many of the “ 4 
— 
half hardy” plants, e.g., Magnolia grandiflora, 
were protected from early December throughout the winter by a 
covering of burlap or lath screens. These plants are designated P. 
The symbols used to designate the data presented in Taylor’s 
