XVIII, 



OATS. 



I. STRUCTURE. 



377. Relationships. — The tribe (Avenae) to which the oat 

 [Ave/ia sativa L.) belongs differs from the tribe {Hordeae) to 

 which wheat, rye and barley belong, in ha\'ing the inflorescence 

 in panicles instead of in spikes, and in having a crooked awn 

 on the back of the flowering glume, instead of a straight awn at 

 the end. To this tribe belong few economic plants. Arrhena- 

 theritm avenaceinn Beauv. is somewhat extensively cultivated 

 in France under the name of Ray Grass. It is only sparingly 

 cultivated in America under the name of Tall Oat Grass. Velvet 



Grass {Holcus lanatits L.) is also 

 occasionally sown as a pasture 

 grass. 



378. The Plant. — The habit of 

 growth of the roots is similar to 

 that of wheat. The culms are 

 somewhat larger in diameter and 

 of rather softer tissue. Environ- 

 ment has a greater influence upon 



of 

 Height of 



becomes erect by the growth on its lower Culm VarieS from twO tO five fcct ; 



side of th« sheath node, not the culm probably the average height is 



three and a half feet. The leaves 

 are more abundant, the blade broader, and the ligule more 

 pronounced than in wheat. 



The Ohio Station found during seven years an average of one 



length of culm of oats than 



Nodes of oats; A, exterior view ; B, cross 

 section of straight culm; C, cross-section winter whcat and ryC 

 showing that a culm after it has fallen 



