Division—Spermatophyta 
Subdivision—Angiospermae 
Class—Dicotyledoneae 
Order—Sapindales 
Family—Aceraceae 
Genus—Acer 
Species—saccharum 
Variety—nigrum. 
HABIT.—Habit, or the general appearance of a plant, is 
an important character of. identification, especially as we become 
more and more familiar with the trees. Two main types are 
recognized, based on the manner of branching of the trunk, the 
upright and the spreading. In the one the trunk extends straight 
upwards without dividing, as is typical in most of the conifers, 
and in the other the trunk divides to form several large branches 
and the broad, spreading crown of most of our broad-leaf trees. 
The crown in either case may be regular in outline or very 
irregular, straggling or straight-limbed. Moreover, the tree 
growing in the open, where there is no crowding and there is 
plenty of light, may differ very greatly from the tree in the 
forest, where the struggle for existence becomes very keen. A 
short, thick trunk and low, spreading, many-branched crown 
characterizes the tree in the open, whereas the forest tree has a 
long, slender, clean trunk and a narrow crown of few branches. 
In the descriptions of trees in this bulletin, unless otherwise 
stated, the habit in the open is the one given. Again, the tree 
may have been injured by storm or insect at some period of its 
growth and its natural symmetry destroyed. Moreover, the age 
of a tree has a great influence on its outline, young trees being 
generally narrow and more or less conical, broadening out as 
they become older. We may say, then, that each tree has an indi- 
viduality of its own, little eccentricities similar to those that make 
people different from one another. And just as we have little 
difficulty in recognizing our friends at a distance by some peculiar- 
ity of walk or action, so are we able to recognize a great many 
trees at a distance by some peculiarity of form or habit. 
LEAVES.—With the advent of spring the buds of our broad- 
leaf trees swell and burst and the leaves come forth and clothe 
the trees with mantles of green, hiding the branches which have 
been bare through the cold winter months. The evergreens, too, 
