GRASSES OF IOWA. 305 



spreading, and somewhat nodding at the tips. Spikelets ovate-oblong, 6 

 to 9 lines (12-18 mm.) long, five to ten-flowered, flowering glumes 

 round on the back, somewhat ventricose, shining, awned. Awns straight, 

 about as long as the glumes. Common in cultivated fields and waste 

 places. July and August. 



This has become a weedy grass in central Iowa. At first introduced 

 as a forage plant by Capt. R. P. Speer in 1889, at Ames, it has spread 

 to railroads and streets. 



DISTRIBUTION. 



Iowa. Ames (1148 Louthan, 909 Pammel; see Shear, Bull. U. S. 

 Dept. Agrl. Div. Agros. 23:18). 



North America. Newfoundland, Manitoba, Maine to New York, 

 District of Columbia (Washington, Conant), Michigan to Minnesota, 

 Nebraska (Grand Island, Pammel 52, 97). 



General. Western Europe, Great Britain, Germany to northern 

 Africa. 



16. BROMUS ARVENSIS. 



Bromus arvensis L. Sp. PI. 77. 1753. Beal. Grasses of N. A. 2: 

 626. 1896. Shear. Bull. U. S. Dept. Agrl. Div. Agros. 23: 20. f. 4. 1900. 



DESCRIPTION. 



Field Brome. A tufted annual or biennial, somewhat geniculate 

 at the base. Culm nearly or quite glabrous, about U to 3 feet (3-6 dm.) 

 high. Sheaths densely soft pubescent; ligule about 1 line (2 mm.) long, 

 lacerate; blades linear, pubescent on both sides. Panicle effuse, broad, 

 apex somewhat drooping; lower rays mostly 4 to 8. Spikelets terete acu- 

 minate at first, becoming slightly laterally compressed when old, about 

 seven to eleven-flowered, J to \\ inches (1^ to 2^ cm.) long, 1! to 2 

 lines (3-4 mm.) broad, smooth or minutely scabrous throughout; empty 

 glumes broad; the lower-subacute, three to five-nerved, 2 to 2-jl- lines (4- 

 5 mm.) long, the upper about seven-nerved, obtuse, 2\ to 3 lines (5-6 

 mm.) long; flowering glume 3^ to 4 lines (7-8 mm.) long, broad, ob- 

 tuse, with the broad, hyaline margin projecting slightly into an obtuse 

 angle just about the middle, apex hyaline, emarginate ; awn inserted 

 below the apex, 3^ to 5 lines (7-10 mm.) long, straight or slightly 

 twisted when old ; palea shorter than its glume. July- August. 



Introduced from Europe. This species is local in a few places, 

 presumably introduced with European grass seed. See figure 215, on 

 page 304. 

 20 



