INTRODUCTION. 
When my Plant Materials pocket manual was issued, in 
1917, an unusually full account was given of characters that 
are not mentioned in the usual handbooks, but the keys were 
based in large part on differences used by the old herbalists,— 
position and other peculiarities of the foliage. The key of 
the present volume utilizes leaf-scar and bud differences in 
the same manner. 
Because the keys of the first volume are as available for 
coniferous evergreens in winter as in summer, this important 
group of trees is not considered here at all; but angiospermous 
evergreens and the few deciduous conifers are treated now in 
even greater fullness. To avoid unnecessary repetition, fam- 
ily descriptions are not repeated here, and the generic charac- 
ters are confined to the direct purpose of the book. 
This purpose, naming our common trees and shrubs when 
without foliage, involves a close accounting for small differ- 
ences between small parts, so that illustrations are more in- 
dispensable than for a Summer Manual leading to the same 
end with the same plants. Such illustrations are inserted in 
the text, where they may be used with convenience. Occa- 
sionally a twig or leaf is pictured of natural size or reduced 
to one-half (or in Magnolia one-fourth) its natural size. Ex- 
cept for these and the self-evident cases of Ailanthus, Aralia 
and Cedrela where details are seen easily without enlarge- 
ment, the essential characters of leaf-scars, bud and pith are 
shown with a uniform enlargement of three diameters, which 
serves the purpose though details sometimes appear small as 
a result. 
Even more necessary than in summer studies, is a good 
pocket-lens of about 12-magnification; and it should be an 
invariable practice to examine carefully a number of buds 
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