106 Bulletin V. 2. 



apparently at the root, the culms are said to be simple. Sometimes 

 the stems or branches ascend immediately, standing vertically, 

 when they are termed erect j they may spread a little at first, and 

 then assume an erect position, the lowermost joints being bent or 

 kneed; such culms are said to be geniculate at base. The basal 

 branches may lie flat upon the ground and spread more or less 

 extensively, taking root at the usually numerous joints, and at 

 definite points sending up erect flowering branches, or branches 

 bearing leaves only; such grasses are said to have a creeping \i2.h\t. 

 Again, one or more of the lowermost branches may not come to 

 the surface at all, or until it has extended through the soil for a 

 greater or less distance. These form the "creeping roots" of 

 grasses, but as just stated, they are true stems or branches, for 

 they are always distinctly jointed, and at the joints there are 

 scale-like leaves — characters never found in roots. The joints of 

 these underground stems may be very short, and from each node 

 mav spring a flowering branch. So condensed may this growth be 

 that the rhizome is entirely concealed, but in perennial grasses it 

 is always present, and in the best turf or sward-forming grasses it 

 is manifest enough. In couch-grass, and especially in Johnson 

 grass, these rhizomes are greatly developed, penetrating the soil 

 in all directions, forming a sward that is excedingly difficult to 

 break. 



Grass stems are usually round or cylindrical, rarely flattened, 

 and generally hollow between the joints or nodes (solid or with 

 pith in the Andropogons, Indian Corn, and a few other grasses.) 



The Leaves. — The leaves of grasses have two distinct parts: the 

 sheath and the blade. The sheath, or basal portion, usually closely 

 surrounds the stem, and is split or open upon the side opposite the 

 blade, or is entire, then forming a closed cylindrical sheath about 

 the stem. When split, the free edges usually overlap each other. 

 At the top of the leaf-sheath, at the point where the blade 

 originates, there is upon the inside usually a thin and delicate 

 prolongation, often very short, called the ligule. Sometimes the 

 ligule takes the form of a fringe of hairs. The leaf-blade is 

 generally narrow, usually many times longer than broad, with 

 nearly parallel edges. Such leaves are called li?iear. From this 

 form the leaves may vary to lajiceolate or ovate in outline. Some- 

 times the narrow leaves have their edges rolled inwards, when 

 they are said to be involute. Occasionally the leaf-blade is very 

 short, and sometimes it is wanting altogether. As to the surfaces 

 of the leaves and sheaths, they may be smooth or rough, or more 

 or less hairy. 



The position of the leaves on the stem is to be noted as affording 

 an easy character for distinguishing grasses from the nearly allied 



