DESCRIPTIONS OF SOME COMMON WEEDS 147 



pound spikes ; empty glumes nearly equal, longer than 

 the flowering glumes, equaling the small lateral awns; 

 awns unequal, the long middle awn horizontal, soon be- 

 coming reflexed. Common in dry, sterile or clay soil 

 southward. 



A. oligantha is a tufted annual, bearing loosely, few- 

 flowered racemes, leaves short; awns all diverging and 

 alike. Common in dry fields, especially southward ; oc- 

 curring as far north as Iowa. A. fasciculata is the sand 

 grass of the plains. It is a perennial with long, spiked 

 panicles. 



Nimble Will (Muhlenbergia racemosa, (Michx.) B. S. 

 P.). A rather stout, upright perennial, with very rough, 

 densely scaly rootstocks, and nearly simple stems, two 

 to three feet high ; densely flowering panicles two to four 

 inches long, contracted into an interrupted, long-pedun- 

 cled spike with sessile branches ; long acuminate-pointed 

 outer glumes nearly equal and exceeding the very acute 

 flowering glume, which is densely bearded at the base; 

 blooms from July to September. Occurs in the northern 

 Mississippi valley, a rapid grower and affords some for- 

 age when young. Troublesome weed. 



Mexican Drop Seed (Muhlenbergia mexicana, (L.) 

 Trin.). An upright or ascending, usually much-branched 

 perennial, one to three feet high, with a scaly, creeping 

 rootstock, numerous flat leaves and contracted, densely 

 flowered panicles ; sheaths smooth ; leaf blades two to seven 

 inches long; panicles lateral and terminal, often included 

 at the base, densely spike-clustered, linear, green and 

 purplish ; spikelets on very short pedicels, the empty 

 glumes nearly equal, about the length of the floral glume, 

 rough on the keel, floral glume lanceolate, acute or 

 mucronate-pointed, three-nerved ; blooms in August. 

 Widely distributed and abundant in all parts of the state ; 

 somewhat variable in form, approaching at times the 

 marsh Muhlenberg in density, but when cut off before 



