132 GRAMINEAE 



1. A. fatua L. WILD OAT. Culms 1 to 3 feet high, erect, stout ; panicle loos 

 and open, the slender branches usually horizontally spreading; spikelets usu- 

 ally 3-flowered ; glumes about 1 inch long ; rachilla and lower part of the shin- 

 ing lemma clothed with long stiff brownish hairs ; florets readily falling from 

 the glumes ; lemma nerved above, about 10 lines long, the teeth acuminate but 

 not awned; awn stout, geniculate, red-brown, twisted below, about 1% inches 

 long. 



A native of Europe, a common weed on the Pacific Coast. Fields and waste 

 places, especially in southern California. 



Var. glabrata Peterm. Differs in having nearly or quite glabrous lemmas. 

 Introduced from Europe, in similar situations with the species. 



Refs A VENA FATUA L. Sp. PI. 80. 1753 ; Thurb. in Wats. Bot. Gal. 2 : 295. 1880 ; Davy in 

 Jepson, Fl. W. Mid. Cal. 53. 1901; Abrams, Fl. Los Ang. 39. 1904. Var. GLABRATA Peterm. 

 Fl. Bern. 13. 1841. Var. gldbrescens Coss. Fl. Alg. 113. 1867; Davy in Jepson, Fl. W. Mid. 

 Cal. 53. 1901 ; Abrams, Fl. Los Ang. 40. 1904. 



2. A. sativa L. CULTIVATED OAT. Similar to A. fatua; florets not readily 

 separating from the glumes; spikelets usually 2-flowered; lemma glabrous; 

 awn straight, often wanting. 



Commonly cultivated and occasionally escaped. 



Kefs. AVENA SATIVA L. Sp. PI. 79. 1753; Davy in Jepson, Fl. W. Mid. Cal. 54. 1901. 



3. A. barbata Brot. Similar to A. fatua; spikelets somewhat smaller, 

 mostly 2-flowered, the pedicels curved and capillary ; lemma clothed with stiff 

 red hairs, the teeth acuminate and ending in fine awns 2 lines long. 



A native of Europe, introduced on the Pacific Coast ; a common weed in fields 

 and waste places. 



Eefs. AVENA BARBATA Brot. Fl. Lusit. 1: 108. 1804; Davy in Jepson, Fl. W. Mid. Cal. 

 54. 1901. 



ARRHENATHERUM ELATIUS Beauv. Tall Oat Grass. This has been collected at 

 Agricultural Station, Amador Co., by Hansen (no. 1737) and in the Berkeley 

 Hills by Davy. It is a native of Europe, often cultivated in the Eastern States 

 as a meadow grass and frequently escaped along roadsides and into waste 

 places. As yet it appears to be rare in California. It can be recognized by the 

 2-flowered spikelet, the upper perfect and awnless or nearly so, and the lower 

 staminate and dorsally awned. A tall perennial with flat blades and long nar- 

 row panicles. (See also Davy in Jepson, Fl. W. Mid. Cal. 54. 1901.) 



36. DANTHONIA DC. 



Spikelets several-flowered, in narrow or open panicles, the uppermost floret 

 reduced. Glumes 2, subequal, much longer than the lemmas and usually ex- 

 ceeding the uppermost floret. Lemmas convex, 2-toothed at apex, with a 

 twisted awn from between the teeth, the awn flat, formed by the extension of 

 the 3 middle nerves of the lemma. Tufted perennials with numerous basal inno- 

 vations and few-flowered simple panicles. Species about 100 in the temperate 

 and warmer region of both hemispheres, only about 8 in North America. 

 (Etienne Danthoine, a French botanist.) 



Sheaths pubescent. 



Spikelets 2 to 4 1. D. americana. 



Spikelets solitary 2. D. unispicata. 



Sheaths glabrous. 



Spikelets on spreading pedicels 3. D. calif ornica. 



Spikelets on short erect pedicels, forming a narrow spike-like panicle 4. D. intermedia.' 





