34 



WEED FLORA OF IOWA 



Chemical Composition. — Mexican drop-seed grass has been 

 chemically investigated by the Dakota, Tennessee and Iowa sta- 

 tions. The Iowa analyses were made at 7 different times between 

 April 29 and July 20 with the following results. The water con- 

 tent varies greatly as does the protein content. 



NATURAL CONDITION 



Fig. 18. Mexican Drop-seed Grass (Muhlenbcrgia mexicana) ; a, b, spikelets. 



