GRASSES OF IOWA. 



137 



DESCRIPTION. 



Nimble Will. A low, 

 ascending perennial with 

 slender, much-branched, 

 wiry culms, i to 2 feet 

 (2-4 dm.) long. Sheaths 

 smooth, pilose at the 

 throat; ligule very short; 

 leaf blade 1 to 2 lines (2- 

 4 mm.) wide, 1 to 4 inches 

 (2-8 cm.) long, scabrous 

 on both sides. Panicles 3 

 to 7 inches (6-14 cm.) 

 Long, slender, branches 

 erect, rather densely flow- 

 ered. Spikelets 1 line (2 

 mm.) long, equalling or 

 exceeding the pedicels; 

 empty glumes minute, un- 

 equal, the lower sometimes 

 obsolete ; flowering glume 

 narrowly lanceolate, pilose 

 near the base, scabrous on 

 the nerves above, terminat- 

 ing in a slender, straight 

 awn, 1 to 2 lines (2-4 mm.) 

 long; palea equalling the 

 glume. Shaded thickets, 

 border of woods, waste ground about dwellings. July to September. 



Nimble Will was originally confined to southeastern Iowa. It has 

 spread northward along the Mississippi, where it is now abundant as 

 far north as Dubuque. It is also spreading in central Iowa. The 

 crass is of little economic importance. 



DISTRIBUTION. 



Iowa. Ames (Pammel, Bessey, Hitchcock) ; Dixon, 735 (Sny- 

 der) ; Fayette (Fink) ; Clinton, 247. (Pammel) ; Manchester, 942 

 (Ball); Libertyville, 935 (Baldwin); Mt. Pleasant, 993 (Witte) ; 

 Muscatine, 516 (Reppert) ; Des Moines, 635 (Pammel); Mt. Plea- 

 ant (Mills) ; Jefferson (Pammel) ; Mt. Ayr, 642 (Beard) ; Red Oak 

 (Holt); Hamilton to Hancock County (Preston); Iowa City (Mac- 

 bride) ; Des Moines (Pammel). 



North America. Maine to New York and Florida; west to Ala- 

 bama. Texas (Kerrville, J. G. Smith), Kentucky (Bell County, 

 Kearney), Missouri, Kansas, Nebraska, Iowa, Illinois, Wisconsin, Min- 

 nesota and Ontario. 



Fig. 93. Muhlenbergia diffusa— a,, empty 

 glumes; b, spikelets; c, flowering glume. (Div. 

 Agros. U. S. Dept. of Agrl. ) 



