GRASSES OF IOWA. 287 



North America. Introduced throughout the west, Wisconsin (La 

 Crosse Pammel) Colorado (Ft. Collins, Crandall; Ft. Collins and Lari- 

 mer County, Pammel). 



General. In Europe, France, Holland, Germany, Switzerland, 

 Austria, Russia to Asia, Caucasus and Siberia. 



2. BROMUS PURGANS. 



Bromus purgans L. Sp. PI. 1: 76. 1753. 



Bromus ciliatus var. purgans Gray. Man. Bot. 600. 1848. (1 ed.) 

 Scribner. Grasses of Tenn. Bull. Univ. Tenn. Agrl. Exp. Sta. 7: 118. 

 /. 168. 1894. Watson and Coulter. Gray. Man. Bot. 670. 1890. (6 ed.) 

 Beal. Grasses of N. A. 2: 619. 1896. Nash in Britton and Brown. 111. 

 Fl. 1: 219. /. 506. 1896. 



Bromus purgans L. Shear. Bull. U.S. Dept. Agrl. Div. Agros 23. 

 39. f. 22. 1900. 



DESCRIPTION. 



Bro.me Grass. A rather stout perennial, 3^ to 7 feet (7-14 dm.) 

 high. Culms erect, smooth or pubescent at the nodes. Sheaths usually 

 coarsely retrorse-pilose ; ligule \ to 1 line (1-2 mm.) long, rather firm, 

 truncate; blades broadly linear-lanceolate. 7^ to 15 inches (15-30 cm.) 

 long, i\ to 7?r lines (5-15 mm.) broad, somewhat auricled at the base, 

 short-pilose on the nerves above or smooth, scabrous or smooth beneath. 

 Panicle large, lav, nodding, mostly 7| to \i\ inches (15-25 cm.) long; 

 lower branches two to four, long, slender, flexuose. Spikelets mostly 

 seven to eleven-flowered, 1 to 1^ inches (2-2^ cm.) long, terete-acumi- 

 nate at first, becoming oblong-lanceolate in outline and somewhat flat- 

 tened ; empty glumes narrow, acuminate, sparsely covered with short 

 pubescence; the lower one-nerved, 2\ to 3^ lines (5-7 mm.) long; the 

 upper broader, three-nerved 3 -J- to \\ lines (7-9 mm.) long; flowering 

 glume lanceolate, acute, or sub-acute; five-nerved, or sometimes with 

 two or more faint nerves when mature, 5 to 6 lines (10-12 mm.) long, 

 with rather short, sparse pubescence over the back, emarginate or shortly 

 bidentate at the apex; awn straight, slender, 2 to 3 lines (4-6 mm.) long; 

 palea 1 to \\ lines (2-3 mm.) long, nearly equalling its glume, rachilla 

 slender, pubescent. July to August. See figure 199, on page 287. 



This is the most widely distributed brome grass in Iowa. The 

 species occurs in woodlands where it was once common. Blue grass in 

 many of our woodlands has taken the place of this and other native 

 grasses. 



