GENERAL DESCRIPTION OF GRASSES. 
A grass possesses the following parts: (1) The root, (2) the stem, (3) 
the leaves, (4) the flowers. 
(1) The roots are the fibrous branching organs which extend down-. 
ward into the ground and appropriate the water or other liquid nutri- 
iment to be conveyed into the stem and leaves. 
(2) A stem that rises above ground, either erect, ascending, or re- 
clining, is called a culm. In some species, in addition to the culm, 
there are horizontal subterranean stems, improperly called roots. They 
are known botanically as rhizomes, and are sometimes several feet long. — 
They may be distinguished from the true roots by their bearing a 
greater or less number of scales and sending out erect branches as 
well as fibrous roots. In some grasses there is a kind of bulb at the 
base of the stem, in which is stored a concentrated mass of food for 
the support of the plant under pecuJiar circumstances, as in protracted 
drought. This bulbous formation is a part of the stem, and not of the 
root. The stem or culm of grasses is usually cylindrical and hollow ; 
sometimes it is more or less compressed or flattened. It is divided at | 
intervals by transverse thickened portions called joints or nodes, at 
which points leaves and sometimes branches are given off. These 
nodes tend also to strengthen the stem. Stems are usually simple and 
unbranched, except af the top, where they commonly divide into the 
more or less numerous branches of the panicle or flowering part. But 
some stems give rise from the side joints to leafy branches, which may, 
like the main stem, produce smaller panicles at the top. 
(3) The leaves take their origin at the nodes or joints in two ranks— 
that is, they are placed alternately on opposite sides of the stem at 
greater or less distances; thus, the first leaf will be on one side, the 
second on the opposite side a little higher up, the third still higher and 
directly over the first, the fourth over the second, and soon. The leaves 
consist of three parts: (1) the sheath, (2) the ligule, and (3) the blade. 
The sheath is that part which clasps the stem. It is generally open on 
one sitle, as will be readily observed in the leaves of a corn-stalk, but in 
some grasses the sheath is partly or even completely closed together 
by the adhesion of the opposite edges. The sheath is analogous to the 
stem or petiole of the leaves of many higher plants. At the point where 
the blade of the leaf leaves the stem, at the top of the sheath and o- 
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