GRAM1NEAE. 149 



Flowering scales glabrous or minutely roughened. 

 Awns straight. 



Nerves of the turgid fruiting flowering scales obscure; sheaths gla- 

 brous, ii. B. secalinics. 

 Nerves of the flowering scale prominent ; sheaths softly and 

 densely pubescent with reflexed hairs. 



Spikelets broadly lanceolate, usually i, or sometimes 2, on the 



longer branches. 12. B. racemosus. 



Spikelets lanceolate, several on the longer branches. 



13. B. arvensis. 

 Awns strongly bent near the base, divergent. 14. B. squarrosus. 



2. Flowering scales awnless, nearly as broad as long. 15. B. brizceformis. 



b. Flowering scales compressed-keeled. 



Flowering scales pubescent; awn 4-6 mm. long. 16. B. breviaristatus. 



Flowering scales minutely roughened ; awn less than 2 mm. long, or none. 



17. B. unioloides. 



1. Bromus inermis Levss. Hungarian Brome-grass. Culms tufted, 8-12 

 dm. tall; sheaths smooth and glabrous; leaves 1.5-2.5 dm. long, 4-6 mm. wide, 

 smooth and glabrous; panicle 1.5-2.5 dm. long, oblong, the axis scabrous, its sca- 

 brous branches ascending, in clusters; spikelets 2-2.5 cm. long, about 5 mm. wide, 

 oblong, erect, the first scale 1 -nerved, the second scale 3-nerved, the flowering 

 scales 10-12 mm. long, 5-7-nerved, awnless, or rarely awn-pointed. In fields and 

 waste places, S. Dak. and Ohio. Introduced from Europe. June-July. 



2. Bromus ciliatus L. Fringed Brome-grass. Wood Chess. (I. F. f. 

 506.) Culms 6-12 dm. tall, glabrous or pubescent. Sheaths often softly pubes- 

 cent, or the lower sometimes sparingly hirsute ; leaves 1-3 dm. long, 4-12 mm. 

 wide, smooth beneath, scabrous and often pubescent above ; panicle open, 1-2.5 

 dm. in length, its branches widely spreading or often drooping; spikelets 5-10- 

 flowered, 2.5 cm. long or less; first scale i-nerved, the second longer, 3-nerved; 

 flowering scales 8-12 mm. long, obtuse or acute, 5-7-nerved, appressed-pubescent 

 on the margins or over the entire surface; awn 4-8 mm. long. In woods and thick- 

 ets, Xewf. to Manitoba and Br. Col., south to Fla. and Tex. Variable. The form 

 known as var. purgans (B. pubescens Muhl.) with the flowering scales pubescent all 

 over, may be distinct. July-Aug. 



3. Bromus erectus Huds. Upright Brome-grass. (I. F. f. 507.) Culms 

 6-9 dm. tall. Sheaths glabrous or slightly pubescent; leaves sparingly pubescent, 

 2-4 mm. wide, those of the culm 1-2 dm. long, the basal about 3 dm. long, very 

 narrow; panicle 7.5-17.5 cm. in length, the branches erect or ascending, the lower 

 2.5-7.5 cm. long; spikelets 1.25-3.75 cm. long, sometimes purplish, 5-10-flowered; 

 empty scales acuminate, the first i-nerved, the second longer, 3-nerved; flowering 

 scales 1-1.2 cm. long, acuminate, very rough -pubescent, 5 -nerved, the intermediate 

 nerves faint; awn 4-6 mm. long. In waste places about N. Y. Adventive from 

 Europe. July-Aug. 



4. Bromus asperMurr. Hairy Brome-grass. (I. F. f. 508.) Culms 6-18 dm. 

 tall, rough. Sheaths strongly retrorse-hirsute. especially the lower; leaves 2-3 dm. 

 long or more. 6-12 mm. wide, rough or often hirsute; panicle 1.5-3 dm. m length, 

 open, the branches usually drooping; spikelets 5-10-flowered, 2.5-3.75 cm. long; 

 empty scales acute, scabrous on the nerves, the first I -nerved, the second longer, 

 3-nerved; flowering scales about 1.2 cm. long, acute, hispid near the margins and 

 on the lower part of the keel; awn 6-8 mm. long. In waste places, N. B. to Mich, 

 and Ky. Naturalized from Europe. July-Aug. 



5. Bromus tectdrum L. Downy Brome-grass. (I. F. f. 509.) Culms 

 1.5-6 dm. tall, erect from an annual root. Sheaths, at least the lower ones, softly 

 pubescent; leaves 2.5-10 cm. long, 2-4 mm. wide, softly pubescent; panicle 5- 

 15 cm. in length, open, the branches slender and drooping, somewhat one-sided; 

 spikelets numerous. 5-8-flowered, on capillary recurved slender pedicels; empty 

 scales acuminate, usually rough or hirsute, the first i-nerved, the second longer, 

 3 nerved; flowering scales 8-12 mm. long, acuminate. 7-nerved, usually rough or 

 hirsute; awn 1. 2-1. 6 cm. long. In fields and waste places, Mass. and R. I. to 

 Ont, south to Md. and Ohio. Naturalized from Europe. Sometimes a trouble- 

 some weed. May-July. 



