132 GRA.MINEAE 



1. A. fatua L. Wild Oat. Cnlius 1 to 3 feet high, ereet, stout ; pauit^'le loose 

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

 ally 3-Howered; glumes about 1 inch long; raehilla 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 awued; awn stout, geniculate, red-brown, tv,'isted below, about 11/2 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 rroiii Europe, in similar situations with the species. 



Eefs.— AvENA FATUA L. Sp. PI. 80. 1753; Thurb. in Wats. Bot. Cal. 2: 295. 1880; Davy in 

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

 Fl. Bein. 13. 1841. Var. glahresccns Coss. Fl. Alg. 113. 1867; Davy in .Jepson. PI. 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 M'anting. 



Connnonl.v cultivated and occasionally escajied. 



Kefs.— AvENA SATIVA L. Sp. PI. 79. 1753; Davy in Jepson, Fl. \V. Mi.l. Cal. 54. 1901. 



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

 mostly 2-tlowered, 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. 



Refs.— AvENA B.VRBATA Brot. Fl, Lusit. 1: lOS. 1804; Davy in .leps,)n, Fl. W. Mi.l. Cal. 

 54. 1901. 



Arriienatheruji 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 meadoAV grass and freciuently 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. "\V. ^lid. Cal. .54. 1901.) 



36. DANTHONIADC. 

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

 reduced. Ghnnes 2, subequal, much longer than the lemmas and usuall.v ex- 

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

 twisted awn from between the teeth, the awn flat, formed bj^ 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 Frendi botanist.) 



Sheaths pubescent. 



Spikelets 2 to 4 , 1. D. amerirana. 



Spikelets solitary 2. D. unUpicata. 



Sheaths glabrous. 



Spikelets on spreading pedicels 3. D. calif oriiica. 



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



