46 A MANUAL OF FARM GRASSES 



STEMS AND LEAVES 



The vegetative parts of grasses, the green parts above 

 ground, consist of stem and leaves. 



Stem. — The stem is the central axis of the plant which 

 bears the leaves and finally the flowers. In most of the 

 common crop grasses the stems are simple and upright, 

 that is they are not branched above ground. However, 

 nearly all grasses stool. This stooling is a vigorous 

 branching at the base, as shown typically by wheat. 

 In technical descriptions the stem is called the culm. 



The stem is usually round (cylindric) but is sometimes 

 somewhat flattened, distinctly so in Canada bluegrass. 

 It is divided into sections (jointed) separated by nodes 

 (joints), the slightly swollen places, discerned distinctly 

 in the straw of wheat and other grains. Many grass 

 stems are hollow, as in wheat, but may be solid or pithy 

 as in corn, sorghum, and Johnson grass. At each node 

 is borne a leaf. In many grasses the nodes are close 

 together at the base of the stem. The crowding of the 

 nodes produces a crowding of the leaves, the latter thus 

 appearing in a tuft at the base. This is true of nearly 

 all perennial grasses such as bluegrass and rye grass. 

 The early shoots remain short with crowded leaves. The 

 stem elongates only when the plant is ready to produce 

 flowering shoots. 



In a few grasses, such as Bermuda grass, the plant 

 produces slender stems or runners which creep along the 

 surface of the ground, taking root at the joints and 

 sending up flower-stems. Such creeping stems are 

 technically known as stolons. 



