148 FORAGE PLANTS AND THEIR CULTURE 



variations observed by him may be thus briefly sum- 

 marized : 



The leaves vary from 4 to 15 inches in length, and are 

 from .25 to .75 inch broad. They may be flat or con- 

 cave or loosely twisted; spreading, drooping, or nearly 

 erect. The number to the culm ranges from 3 to 8. 



The stems are usually green, rarely reddish or bluish, 

 18 to 55 inches tall, .05 to .15 inch in diameter, erect 

 to decumbent. The nodes are usually brown, but vary to 

 green. 



The heads are normally cylindrical, with a rounded 

 or abruptly pointed tip, but on some plants they have 

 a long tapering apex or a tapering base, or both. They 

 vary in length from 1 to 12 inches ; in diameter, from .2 to 

 .4 inch ; in color they are usually green, sometimes purple. 



The blooming period of the earliest individuals was 

 18 days earlier than the latest ones in 1907. This differ- 

 ence doubtless fluctuates according to the season, being 

 lengthened by cool weather and shortened by warm 

 weather. 



The life period probably varies greatly. Some in- 

 dividuals are apparently annual, and others survived only 

 two years. Most of the plants were still vigorous at the 

 end of nearly six years. 



The vigor of individuals varies greatly. 



The number of culms per plant ranges from a few up to 

 280. 



The yield of hay to the plant ranges from .01 pound to 

 1.35 pounds. 



The only positive correlation found was that between 

 weight and height. 



136. Disease resistance. The most serious disease 

 that has affected timothy in America is rust. At Arlington 



