GRASSES OF IOWA. 



183 



Muhlenbergia Mexicana (L.)Trin. Beal. Grasses of N. A. 2: 252. 

 1896. Nash in Britton and Brown. 111. Fl. 1: 142. /. 321. 1896. Scribner. 

 Bull. U. S. Dept. Agrl. Div. Agros. 7: 106. f. 100. 1900. (3d edj 



Agrostis Mexicana L. Mant. 1: 31. 1767. 



Agrostis filiformis Muhl. Gram. 66. 1817. 



Agrostis lateriflora Michx. Fl N. Am. 1: 53. 1803. 



DESCRIPTION. 



Mexican Drop Seed. An upright or ascending, usually much 

 branched perennial i to 3 feet (2-6 dm.) high, with a scaly, creep- 

 ing rootstock, numerous Bat leaves and contracted, densely-flowered 



panicles. Sheaths longer or, 

 shorter than the internodes, 

 smooth; ligule \ line (1 mm.) 

 or less long; leaf-blades 1 to 3 

 lines (2-6 mm.) wide, 2 to 7 

 inches (4-14 cm.) long. Spike- 

 lets about 1 line (2 mm.) long 

 on very short pedicels; empty 

 glumes nearly equal, acuminate- 

 pointed, about the length of the 

 floral glume (a little shorter or 

 sometimes a little longer), scab- 

 rous on the keel; flowering 

 glume lanceolate, a:ute or 

 mucronate-pointed, three-nerved, 

 pilose near the base and on the 

 callus. Palea a little shorter 

 than its glume, very acute. 



Mexican drop seed is a widely 

 distributed grass, abundant in 

 all parts of the state. It is some- 

 what polymorphic. Ordinarily 

 the spikes approach in density 

 the M. glomerata, but when 

 cut off before heading out the 

 spikes are more slender, and 

 might readily be mistaken for 

 another species. This is the state 

 called var. filiforme. 



Fig. 9tj Muhlenbergia Mexicana — a, b, 

 spikelets. (Div. Agros. U. S. Dept. of Agrl. ) 



