GRAMINEAE (GRASS FAMILY) 163 



Panicle open. 



Lemma less than 7 mm. long. 

 Panicle 2-3 dm. long ....... . . 6. B. arvensis. 



Panicle less than 1 dm. long ....... 8. B. racemosus. 



Lemma 9-10 mm. long ; panicle drooping ..... 4. B. commutatus. 



Awn short or none ; lemmas very broad ...... 6. B. brieae/ormis. 



Awn bent or twisted ....... . . . 7. B. japonicus. 



Lemma narrow f hwn over 1 cm. long. 

 Panicle open, drooping. 

 Awn about 1.5 cm. long ..... . , . . 8. B. tectorwm. 



Awn 2-3 crn. long ........... 9. B. sterilis. 



Panicle compact, ovoid, erect ....... . . 10. B, rubens. 



Perennials. 



Panicles large, open and drooping. 

 Sheaths shorter than the internodes. 



Lemma smooth on the back, ciliate-pubescent along the margins . 11. B. ciliatus. 

 Lemma evenly pubescent all over ........ 12. B.purgans. 



Sheaths longer than the internodes, much overlapping. 



Sheaths sparsely pubescent except a conspicuous ring at summit . 13. B. altissimus. 

 Sheaths densely pubescent ......... 14. B. incanus. 



Panicles small, narrow, erect or nearly so. 

 First glume 3-nerved ........... 15. B. Kalmii. 



First glume 1-nerved ........... 16. B. erectus. 



1. EUBROMUS Godron. Annuals or biennials ; glumes rather broad ; lem- 

 mas broadly elliptical. Species all introduced. 



1. B. SECALinus L. (CHEAT or CHESS.) Culms 4-9 dm. high; sheaths smooth 

 and strongly nerved; blades sparingly pilose above; panicle open, Us branches 

 somewhat drooping ; spikelets 5-15-flowered, glabrous ; glumes 

 5-7 mm. long; lemma 8-11 mm. long, becoming at maturity 

 convex, thick and inrolled at the margins, awns short and 

 rather weak. Fields and waste places, common. The florets 

 are somewhat distant, so that, in side view, openings are visible 

 along the rhachilla at the base of the florets. (Nat. from Eu.) 



2'. B.'HORDEXCEUS L. (SOFT CHESS.) Culms 1-6 dm. high ; 

 whole plant more or less pubescent ; panicle erect and con- F ? . .j, 

 traded; spikelets 6-10-flowered ; lemma 9-10 mm. long, softly 

 pilose, awn about 1 cm. long. (B. mollis L.) Fields and waste places, infre- 

 quent, N. S. to Va. Var. LEPTOSTACHYS (Pers.) Beck. Spikelets glabrous or 

 merely scabrous. Del. to D. C. (Adv. from Eu.) 



3. B. RACEM6sus L. Culms 3-6 dm. high ; sheaths pubescent; panicle short 

 (not over 7 cm. long), upright; spikelets 5-8-flowered, glabrous; glumes 6-8 

 mm. long ; lemma 7 mm. long, with an awn about 6 mm. long. Waste places, 

 Que. to Del., rare. (Adv. from Eu.) 



4. B. COMMUTATUS Schrad. Differs from the preceding in having an open 

 drooping panicle as much as 1.5 dm. long, and usually longer awns. Waste 

 places throughout, especially in the East. Florets more closely imbricated than 

 in B. secalinus, so that in side view no openings are seen at base of florets; 

 lemmas thinner and not inrolled at the margins. (Adv. from Eu.) 



5. B. ARVENSIS L. Culms 3-9 dm. high, erect or geniculate at the base ; 

 sheaths pubescent; panicle large, open, with long drooping branches; glumes 

 4.5-6 mm. long; lemma 7-8 mm. long, smooth or minutely scabrous; awn 

 about as long, straight or slightly bent. O. (Stair) and Mo. (Bush). (Adv. 

 from Eu.) 



6. B. BRIZAEFORMIS Fisch. & Mey. Culms 1-4 dm. high ; panicle open and 

 drooping ; spikelets broadly ovate, the larger as much as 2 cm. long and 1.3 cm. 

 wide, awnless. Mass, to Del., Mich., and Ind. (C. P. Smith) ; rare. (Adv. 

 from Eu. ) 



7. B. JAPONICUS Thunb. Culms 1.6-6 dm. high ; panicle open and drooping, 

 one-sided ; spikelets linear, 2.5 cm. long, 6-12-flowered ; lemmas glabrous, 9 

 mm. long, with a bent or twisted awn about 12 mm. long. (B. patulus Mertens 

 & Koch.) Near Boston, Mass. (Swan); Lafayette, Ind. (Dorner). (Adv. 

 from Eu. ) 



