1D18] 



The Grasses op Illinois 



401 



Lemmas smooth or scabrous, not pubescent, 

 b. Second glume 3 -nerved. 



c. Lemmas awnless or awn-pointed; plants generally smooth thruout; 



perennial by long, running rootstocks. B. incrmis 



cc. Lemmas with long, scabrous awns; sheaths pilose-pubescent; annuals. 



B. villosus 

 bb. Second glume 5- to O-nerved ; plants without running rootstocks. 



c. Spikelets with the w idth more than half the length ; lemmas very 



broad, awnless or awn-pointed. B. brizaeformis 



cc. Spikelets with the width always less than half the length; lemmas 



narrow or ovate, with an awn at least 3 mm. long. 



d. Lemmas thick, the margin inrolled at maturity, the awn slender 



and weak, 3 to 5 mm. long; sheaths glabrous. B. secalinus 



dd. Lemmas thin, with a transparent edge, not inrolled at maturity, 



the awn strong, 5 to 8 mm. long; sheaths pubescent. 



B. pratensis 

 Lemmas pubescent, either along the margin or over the entire surface, 

 b. Awn as long or longer than the lemma; annual species with the panicle 

 branches drooping. B. tcctorum 



bb. Awn considerably shorter than the lemma. 



c. Lemmas pubescent along the margin and sometimes at the base. 



B. ciliattts 

 cc. Lemmas evenly pubescent over the entire surface. 



d. Lemmas densely long, silky pubescent; lemma 8 to 10 mm. long, 



the awu 2 to 3 mm. B. kalmii 



dd. Lemmas sparsely short, appressed pubescent, 10 to 12 mm. long, 



the awn 4 to 8 mm. B. yurgans 



258 



Figs. 254-261.— Spikelets: 254, B. hrisaeformis ; 255, B. ciliatus ; 256, B. 

 incrmis; 257, B. kalmii; 258, B. pratc7isis; 259, B. piirgans; 260, B. secalinus; 

 261, B. tcctorum 



Bromus brizaeformis Fiseh. and Mey. 

 (Fig. 254) 



Culms 6 inches to 2 feet tall, smooth, slightly pubescent at the 

 nodes ; sheaths pubescent, shorter than the internodcs ; blades 4 to 8 

 inches long, 1 to 4 mm. wide ; panicle open, drooping ; spikelets 10 to 

 20 mm. long and 9 to 13 mm. wide, lemmas awnless, smooth, 8 to 10 

 mm. long. 



This annual species was introduced from Europe aud is rare in 

 America. 



RICHLAND CO. Parkersburg, Eidgeway, June, 1902. 



