16 



59. Spikelets less than 6 mm. broad iu flower 4 B. arvensis. 



59. Spikelets more than 6 mm. broad in flower. . . 2a B. racemosus commutatus. 



60. Awn more than 15 mm. long 61 



60. Awn much less than 15 mm. long, sometimes wanting 62 



61. Awn usually more than 35 mm. long 1 1 a B. maximus gussoni. 



61. Awn usually less than 30 mm. long 13 B. sterilis. 



62. Awn usually less than 3 mm. long 27 B. inermis. 



62. Awn usually more than 3 mm. long 16a: B. ciliatus laeviglumis. 



I. BROMUS PROPER. 



A. Annuals or sometimes biennials vnth empty glumes rather broad and the flowering glume 

 broadly elliptic to oblong-elliptic. Species all introduced. 



1. BROMUS SEC ALINUS L. Sp. PI. 1: 76. 1753. Serrafalcus secalinus Bah. Man. 

 Brit. Bot. 374. 1843. (Fig. 1.) 



An erect annual. Culm 3-7 dm. high, smooth throughout or somewhat pubescent at 

 the nodes. Sheaths typically smooth, sometimes the lowest sparsely pilose-pubescent; 



ligule about 1 mm. long, trun- 

 cate, somewhat irregularly den- 

 tate; blades mostly 1-2 dm. 

 long, linear-lanceolate, with 

 coarse, sparse hairs above, 

 smooth beneath. Panicle about 

 8-18 cm. long, at first erect, 

 the upjjer part drooping in 

 fruit, ijyramidal in outline; 

 lower hranches 3-5, unequal. 

 Spikelets uroid-lanceolate, becom- 

 iugsomcwhat laterally compressed 

 and turgid in fruit, 10-18 mm. 

 long,i 6-8 nun. bi'oad in fruit; 

 empty glumes smooth, obtuse, 

 the lower 4-6 nmi. long, 3-5- 

 nerved, the upper broader, 6-7 

 mm. long, 7-nerved; flowering 

 glumes 7-nerved, 6-8 mm. long, 

 elliptic, obtuse, smooth or sca- 

 brous, having the margin strongly 

 involute in fruit, shortly biden- 

 tate at the apex icith the undu- 

 late awn mostly 3-5 mm. long, 

 inserted al)out 1 nun. below 

 the ajiex; }xdea. equal to or 

 only very slightly shorter than its 

 glume. 

 General distribution: This species, 

 introduced from Europe, is 

 very generally dist r i b u t e d 

 throughout the United States. 

 (J. C. Parlin 566). Ontario: Gait (W. 



rio. 1. — Bromus secalinus: a, spikelet. 

 Specimens examined. — Maine: N. Berwick 



Herriott). Connecticut: Fairfield (E. H. Eames). Xew York: Oxford (F. Y 



1 All measurements of spikelets and glumes are exclusive of the awns. 



