GRASSES OF IOWA. 285 



b. Panicle small, contracted; spikelets small, 12-15mm. long, not 



compressed; awn 6-9mm. long B. hordeaceus!' . 



(a) Spikelets glabrous or scabrous throughout. 



— B. hordeaceus var. glabrescens. '". 



c. Panicle large, contracted in fruit, l-2dm. long, spikelets large, 



2-4 cm. long, strongly compressed laterally; awn 4-7mm. 



long B . marginatus .". 



(a) Panicle larger, 2-3dm. long, awn slightly longer. 



— B. marginatus var. latior .'- . 



d. Panicle large, 1.5-2.5 dm long, pyramidal; spikelets com- 



pressed, 2.5-3cm. long; awn 7-10 mm. long. 



— B. carinatus .*? . 

 2. Flowering glume glabrous or roughened. 



a. Awn straight or merely undulate. 



(a) Sheaths glabrous, the lower sparsely pubescent; spikelets 



broadly lanceolate in fruit; flowering glumes turgid, 

 the margin strongly involute in fruit; undulate awn 

 usually 3-5mm. long; palea equalling or only slightly 

 shorter than the glume B. secalinus . ,4 . 



(b) Sheaths densely pilose-pubescent; panicle small, typically 



simple; spikelets always acute, awn straight, 5-8 mm. 

 long; Palea shorter than the glume. 



— B. racemosus var. commutatus . 18 . 



(c) Sheaths as in last; panicle larger, broad, compound; 



spikelets lanceolate, 2cm. or over long; awn straight, 

 7-10 mm. long; palea shorter than the glume. 



— B. arvensis.™. 



b. Awn twisted and strongly divaricate at maturity. 



(a) Spikelets usually more than 5mm. broad in flower. 



— B. squarrosus . '" . 



(b) Spikelets usually less than 5 mm. broad in flower. 



B. patulus:\ 



1. BROMUS INERM1S. 



Bromus inermis Ley ss. Fl. Hal. 16. 1761. Scribner. Grasses of Tenn. 

 Bull. Univ. Tenn. Agrl. Exp. Sta. 7: 118 /. 169. 1894. Beal. Grasses, of N. 

 A. 2: 612. 1896. Scribner. Bull. U. S. Dept. Agrl. Div. Agros. 7: 296. 

 /. 290. 1900. (3 ed) 



Schedonorus inermis Beauv. Agrost. 99. 1812. 



DESCRIPTION'. 



Smooth Brome or Hungarian Brome Grass. An erect peren- 

 nial, 2 to 5 feet (6-9 dm.) high, with creeping root-stocks, open panicles. 

 5 to 7 inches (12-18 cm.) long, and five to nine-flowered, awnless spike- 

 lets, 1 to \\ inches (2-3 cm.) long. Sheaths striate, smooth, or the lower 

 ones pilose; leaf-blades 4 to 8 inches (10-20 cm.) long, 3 to 4 lines (6- 

 8 mm.) wide, somewhat scabrous, the lower often sparingly pilose. 



