138 TRIANORIA. DIGYNIA, agropyron.. 



Rooi articulated, white, extensively creeping. Culm about 2 feet 

 high. Leaves broad-linear, scabrous on the upper surface, 

 sometimes a little glaucous. Sheaths smooth. Stifiule very- 

 short, truncate. Sfiike 3 — 4 inches long. Rac/iis flexuous, 

 jointed, compressed. Caiy.v nearly equal, acute ; florets alter- 

 nate. Inferior valve of the corolla smooth, nerved, mucronate, 

 sometimes with a short bristle at the tip ; superior valve shorter, 

 emarginate, ciliate on the sides. Stamens 3 ; anthers large, 

 pale yellow. 



Hab. In fields and cultivated grounds ; common. July. Intro- 

 duced ? Couch-grase. 



2. A. caninum R. ^ S. : spikelets about S-floweredj 

 compfessed ; glumes 3-nerved, and, as well as the florets, 

 armed with a bristle at the tip; root fibrous. Roem. ^° 

 Schult. \\, p. 75G, Triticvm caninum Sp. p/. BO. Smith 

 Fl. Brit. I. p. 159. Eng. Bot. t. 1372. Muhl. Gram. 

 p. 196. Elymus cnninns f^^ i 1 1 d. Spec. I. p. 469. 



Root perennial. Culm 2 — 3 feet high, erect or oblique. Leaves 



flfit, smooth. Stif2ule almost wanting. Sfiikelets sometimes 



6-fto\vered. Glumes and the eJiterior valve of the corolla ter* 



minating in a straight scabrous bristle longer than the flowers. 



Hab. In Delaware. Muhlenberg. Probably introduced, 



44. SECALE. L 



Flowers spiked. Spikelets sessile on the teeth of the 

 racfiis, 2 — 3-flowered ; the terminal floret abortive. 

 Calyx 2-'valved ; glumes subulate, opposite, shorter 

 than the florets. Inferior valve of the corolla terminat- 

 ing in a long bristle. Ge?i. pi. 127. Ai''utt. Gen. I. 

 p.'sS. R em. ^ Sell u It. Ge??. 350. P.de Beau v. 

 t. XX. f. 6. Trin.Jgrost.l06. Rye^ 



S. cerealc. L.; glumes and bristles scabrous-ciliate ; co- 

 rolla smooth. fVilld. Spec. I. p. 471. Pursh Fl. I, 

 p. 90. Roem. ^ Schult. 11. p. 773. 



Root annual or biennial. Culm 3 — 4 feet higb. Leaves broad- 

 linear, smooth. S/iike 4—6 inches long, dlumes ciliate, sub- 

 ulate. Inferior valve of the corolla 3-nerved, terminating in a 

 long scabrous bristle. 

 Hab. In neglected fields: scarcely naturalized. June. 



45. ELYMUS. L. 



Flowers spiked. Spikelets 2 or more at each joint 

 of the racliis, 3 — 9-flovvered, Glumes (involucrum L. 

 &c.) geminate, subulate. Inferior valve of the corolla 

 entire, mucronate, or with a short bristle at the tip- 



