The rolled or folded character of the bud-shoot is very difficult to accurately determine (with- 

 out special equipment) for the grasses with narrow leaves (2 to 4 mm.), such as the fine-leaved 

 fescues, many of the bluegrasscs and the bents. The use of this character as a point of separation for 

 such grasses has therefore been avoided in so far as possible. 



The arrangement of the leaves in the bud-shoot may be determined by cutting the shoot across 

 below the ligule of the uppermost leaf and examining the section with a magnifier. 



2. Sheath 



The sheath is the tubular basal portion of the leaf surrounding the stem or the young growing 

 leaves. Sheaths looked at in cross-section may range from distinctly flattened, as in orchard grass, 

 to round, as in timothy. 



Sometimes the midrib extends downward into the sheath and the sheath is said to be keeled. 

 The sheath is generally split to the base or node and the margins are overlapping as illustrated below. 

 Some grasses, notably the bromegrass and cheats (Bromus spp.), are closed to near the top. 

 This character needs careful examination for in some cases a closed sheath is easily split by rough 

 handling. 



Split 



Spill, margins 

 overlapping 



Closed 



The surface of the sheath may be rough to the touch or more or less covered with hairs or 

 it may be smooth (without roughness or hairs). Frequently we find sheaths with purple or reddish 

 tints. These tints, except in a few cases, are not reliable as a means of identification. Where color is 

 used the lowermost sheaths should be examined at or just below the soil surface. In some cases the 

 margins of split sheaths are helpful in distinguishing one grass from another. Most grasses have 

 margins that are thin and hyaline or paper-like while in some, one or both margins may be distinctly 

 hairy. 



3. Auricles 



Large 



Small 



Absent 



