CHAPTER XXVII 
THE CONIFERS (GYMNOSPERMS) —FORESTS 
290. General Characteristics. — In passing from the ferns 
to the conifers, usually known as evergreens, we go from a 
lower to a higher order of plants. None of the algae, fungi, 
mosses, or ferns bear seeds, but all reproduce by spores or 
by fertilized eggs. Most of the evergreens are seed-bearing 
trees which vary in size, but which are alike in having trunks 
that taper from the base to tip without dividing. Such 
trunks are called excurrent , while the trunk of the elm which 
divides repeatedly is called deliquescent. (See Figure 316.) 
The conifer group contains the largest plants in the world 
and those which live to the greatest age. Their foliage is 
usually composed of dark green, needle-like leaves which 
remain attached to the tree for two or three years. Thus 
the trees always have some foliage and so are termed “ ever¬ 
green.” 
291. Pine Tree. — The pine illustrates the plants of this 
family. The pine has all the parts of a flowering plant 
— stem (trunk), branches, roots, leaves, seed-producing 
organs, and fruit (cones). 
Stem. — The trunk does not divide, — a marked character¬ 
istic of conifers. In a forest where trees are crowded to¬ 
gether and there is in consequence a struggle to get light, the 
trunks grow tall and most of the branches are near the top. 
A cross section of a stem shows a series of rings, known 
as annual rings, by which the approximate age of the tree 
can be told. In the spring when all the conditions are at 
their best and growth is rapid, the cells of the tree are 
341 
