GRASS FAMILY 



171 



'1. Avena fatua L. 

 Wild Oat. Fig. 386. 



Azena jatua I.. S\>. PI. SU. 1753. 



Culms 30-60 cm. tall, erect, stout ; panicle loose and 

 open, the slender branches usually horizontally spread- 

 ing; spikelets usually 3-flo\vered; glumes about 2.5 cm. 

 long: rachilla and lower part of the shining lemma 

 clothed with long stiflf brownish hairs ; florets readily 

 falling from the glumes ; lemma nerved above, about 

 2 cm. long, the teeth acuminate but not awned ; awn 

 stout, geniculate, red-brown, twisted below, about 3 

 cm. long. 



A common weed on the Pacific Coast; introduced from 

 Europe. Apr.-Tune. Type locality, European. 



Avena fatua glabrata Peterm. Fl. Bien. 13. 1841. {A. fatua glabrescens Coss. Fl. Alg. 113. 1867.) 

 Differs in having nearly or quite glabrous lemmas. Introduced from Europe, in situations similar to those 

 of the species. 



2. Avena sativa L. 

 Cultivated Oat. Fig. 387. 



Ai-cna satka L. Sp. PI. 79. 1753. 



Similar to A. fatua; florets not readily separat- 

 ing from the glumes; spikelets usually 2-flowered; 

 lemma glabrous ; awn straight, often wanting. 



Commonly cultivated and occasionally escaped. Apr. -June. 

 Type locality, European. 



3. Avena barbata Brot. 

 Slender Wild Oat. Fig. 388. 



Arena barbata Brot. Fl. Lusit. 1: 108. 1804. 



Similar to A. fatua; spikelets somewhat stnaller, 

 mostly 2-flowered, the pedicels curved and capillary ; 

 lemma clothed v/ith stiff red hairs, the teeth 

 acuminate and ending in hne awns 4 mm. long. 



A native of Europe, introduced on the Pacific Coast; 

 a common weed in fields and waste places. March-June. 

 Type locality, European. 



40. ARRHENATHERUM I'.eauv. Ess. Agrost. 55, 152. pi 11, f. r>. 1812. 



Spikelets 2-flowered. the lower floret staminate, the upper perfect, the rachilla disarticu- 

 lating above the glumes and produced beyond the florets; glumes rather broad and 

 papery, the nrst 1-nerved, the second a little longer than the first and about as long as 



