30S 



GRASSES OF IOWA. 



terete at first, I to i-i inches (2-2.5 cm.) long, 2^ to 3 lines (5-6 mm.) 

 broad, becoming somewhat laterally compressed at maturity, smooth 

 throughout; empty glumes rather broad, the lower narrower, acute, 

 three-nerved, 2 to 3 lines (4-6 mm.) long; the upper obtuse, five-nerved, 

 6 to 8 mm. long; flowering glume nine-nerved, the marginal ones faint, 

 3^ to 4^ lines (7-9 mm.) long, broad, obtuse, with a hyaline margin, 



Fig. 217. Bromus patu!us—a, empty glumes; b, 

 flowering glume. (,Div. Agros. U. S. Dept. Agr.) 



obtusely angled above the middle, and an emarginate apex; awn 4 to 5 

 lines (8-10 mm.) long, stout, somewhat twisted and strongly divaricate 

 at maturity, inserted below the apex ; palea conspicuously shorter than 

 its glume. Introduced. July-August. 



