28 ANDROPOGONEAE 



consist of 5 to lU subdivisions 2 to 3 inches long and 34 0^ 

 an inch in diameter all arising from the top of the culm. 

 There are numerous crowded spikelets covered with whitish, 

 spreading, silky, stiff hairs forming a plume like panicle. 



One species of the genus (Sorghastrwn nutans) 

 which occurs sparingly in the mountains is eaten by stock 

 when green, but is of little importance because there is little 

 of it, and that little is not very good. With this exception 

 the native species of the tribe are rarely if ever touched by 

 grazing animals. When first beginning to grow in the 

 summer if other feed is scarce they may be eaten. Usually 

 however, they do not start until after other plants have grown 

 and they are allowed to dry, when they are of no value. The 

 other native species listed in detail below are not of sufficient 

 importance to receive notice here. 



Johnson Grass {Sorghnm hdapense (L) Pers.) is 

 never referred to as a sage grass, so far as the author 

 knows, but it is related to them and belongs in the same 

 tribe. It is too well known to need description. It has very 

 pronounced enemies and some friends, because under certain 

 conditions it is a very troublesome plant and under others it 

 is quite beneficial. The difficulty of keeping these facts 

 separte in one's mind is the cause of the sometimes violent 

 denunciation and equally strenuous upholding of the plant in 

 farming comnuinities. Johnson grass is thoroughly at home 

 in a ricli moist soil in a hot climate and grows luxuriantly. 

 It is so thoroughly able to "crowd" that it soon rules 

 supreme in such locations.* It will not grow in a very dry 

 soil and is easily dried out in an arid region. For this very 

 reason there is little probability of its ever becoming a serious 

 pest any place in the arid region. It may become considerable 

 of an inconvenience however in cultivated irrigated fields, 

 becai^se it gets on the ditches and drops its seeds in the irri- 

 gating water and is planted in the sediment when the water 

 sinks into the ground. It has caused some trouble to alfalfa 

 irrnwers in tlie ATesilla Vallev but there is little doubt that 



