AVENE^. 383 



2. A. Hookeri Scribn. Hack. True Grasses 133 (1890). A. ver- 

 sicolur Hook. Fl. Bor. Am. 2: (1840), notVill. A. 2^raiensis L. var. 

 Americana Scribn. Coult. Bot. Gaz. 11 : 177 (1886). 



An erect smooth perennial, ^-40 cm. high. Ligule ovate, 

 acute; blades narrow, 5-20 cm. long. Panicle simple, 8 cm. long, 

 2 cm. broad. Spikelets erect, shining, 4-5-flowered; empty glumes 

 lanceolate, subequal, 3-nerved, scarious above, about as long as the 

 spikelet; floral glume lanceolate or oval-lanceolate, 12 cm. long, 

 lower part scabrid, the upper scarious, 5-nerved, awn near the mid- 

 dle, reaching 1 cm. above its glume; upper florets gradually shorter; 

 palea oblanceolate, two-thirds as long as its glume, keels ciliate. 



Montana, Scribner, WiUiams 581; Yellowstone Park, Tweedy; 

 Saskatchewan, Bourgeau; N. Trans. Cont. Surv., Canhy & Sci'ih- 

 ner 372. 



Montana and British America. 



3. A. BAEBATA Brot. Flor. Lusit. 1:108(1804). A. hirsuta 

 Roth. Cat. 3: 19 (1806). A. at]ierant]ieraVve%\. Gyp. et Gram. Sic. 

 30 (1826). A.fatna\\\.m. Lib. Spec. 6 (1824). A. segeiaJis 

 Bianca, Nym. Consp. 810 (1878). A. sesquiteria Hort. Steud. Nom. 

 Ed. 1:95 (1821). 



An erect glabrous annual, 60-100 cm. high. Leaf-blades sca- 

 brous, flat, 4-25 cm. long, 3-7 mm. wide. Panicle loose, 20-30 

 cm. long, with unequal filiform pedicels. Spikelets 2-flowered, 

 narrow, drooping; empty glumes oval-lanceolate, subequal, about 

 2.5 cm. long, 9-nerved; floral glume membranous, lanceolate, 2.3 

 cm. long (including 2 slender teeth), 5 mm. wide, 7-nerved, hairy 

 below, some of them 5 mm. long, awn starting near the middle, 2-4 

 cm. long, with several firm twists, abruptly bent near the middle; 

 palea oblanceolate, 13 mm. long, 2 mm. wide, the nerves clothed 

 with very short diverging hairs. Much like A. fatua, from which 

 it differs in having a floral glume thinner, narrower, a little shorter, 

 7-nerved, with two shorter teeth, hairs on the back longer and 

 more numerous. 



Lower California, Palmer 668. 



Introduced into Southern California. 



4. A. sTERiLis L. Sp. Ed. 2: 118 (1762). Animated Oats. A. 



