GRASS FAMILY. 



53 



cent; panicle 5 to 12 in. long, 1£ to 21 lines wide, pubescent, strict, 

 narrow, more or less densely-flowered, often purple-tinged; branches 

 erect, somewhat crowded, all but the longest bearing spikelets to the 

 base, longest 2£ in. long; spikelets about 4 lines long, narrow, 2 to 

 ^-flowered; lower bract narrow, acute, about } shorter than the broad 

 upper one; bractlets not spreading nor very remote, imbricate, 3 to 4 

 lines long, narrow, minutely puberulent, long subulate-pointed; awn 

 stout, about twice the length of its bractlet. 



Dry, open ground or open woods and thickets; Coast Ranges north- 

 ward to Oregon and in the Sierra Nevada: Berkeley hills; Mt. 

 Tamalpais; Olema. Apr. -Sept. 



20. AVENA L. Oats. 

 Ours annual. Stems sub-solitary. Leaf-blades flat. Panicle lax; 

 the branches unequal, and bearing few, pendulous spikelets on 

 slender, geniculate, abruptly clavate pedicels. Spikelets 2 to many 

 (rarely only l)-flowered, the uppermost flowers staminate or abortive. 

 Bracts 2, persistent, unequally nerved. Rachilla jointed above the 

 bracts between the perfect flowers. Bractlet rounded on the back, 

 the apex (in ours) shortly 2-fid, the back bearing a stout awn, mostly 

 geniculate and twisted below; palea narrow, 2-dentate or 2-fid, 

 2-keeled. Scales 2-fid. Stamens 3; anthers sub-basifixed. Ovary 

 and achene hairy, at least at the top; styles short, distant. (Avena 

 the old Latin name for Oats.) 



Awn short or often obsolete, not geniculate; bractlet 7-nerved, glabrous or with 



a few long hairs at the base 2. A. sativa. 



Awn 10 to 24 lines long, geniculate. 

 Bractlet acute but not awn-pointed, 9-nerved, the 2 marginal nerves fine, 



sometimes not continued to the apex I. A. fatua. 



Bractlet acuminate, awn-pointed, 7-nerved 3. A. barbata. 



1. A. fatua L. Wild Oats. Stems stoutish, 2 to 3£ ft. high; 

 ligule short, lacerate; blades long and broad, scabrid: panicle 6 to 14 

 in. long; branches few at a node, very unequal, long and filiform; 

 spikelets drooping, 2 to 3 (rarely only l)-flowered, broad; bracts 

 subequal, ovate-lanceolate, acute, 10 to 12 lines long excluding the 

 awn, 9 to 11-nerved; bractlet less than 10 lines long, acute, 2-fid, 3J 

 lines wide, firm, thinly hairy with usually yellowish hairs, especially 

 below, brown, 9-nerved; that of the uppermost flower sub-glabrous; 

 awn from near the middle of the bractlet, stout, 10 to 20 lines long, 

 geniculate; palea about 7 lines long, and 14 wide, with short diver- 

 gent hairs on the nerves. 



Not uncommon in the Bay Region: San Jose; Mt Hamilton; 

 Danville and Livermore. May-Aug. 



Var. glabrescens Coss. Bastard Oats, is distinguished by 

 having the bractlet naked except for a few short hairs at the base, and 

 sometimes a thin pubescence along the margins, in which it approaches 

 A. sativa; from the latter it may always be distinguished by the 

 longer and geniculate awn and the wider 9-nerved bractlet. intro- 

 duced at San Bernardino and San Jose acc. to Dew T ey; Berkeley, 

 Davy. 



