

GRASS FAMILY. 55 



Panicle-branches short, erect, the whorls not widely separated. 



Spikelets small. 3 to 4 lines long; lower bract only about % shorter than the 

 upper; bractlets imbricate, minutely puberulent; panicle-branches mostly spikelet- 

 bearing to the base 3. T. canescens. 



1. T. barbatum Steud. Brome-like Oat-grass. Annual; stem usually 

 solitary, 2 to 3 ft. high; sheaths hirsute with spreading hairs arising from 

 minute tubereulations, glabrescent in age; blades 6 in. long, 2 to 3 lines wide, 

 pilose-eiliate when young, sub-glabrous with age; panicle lax, 4 to 9 in. long; 

 branches slender, sub-erect, lower bearing 2 to 4, upper only 1 spikelet; spike- 

 lots (i to 12 lines long, 2 to 3 lines wide, 5 to 8-flowered, much flattened, 

 resembling those of a Bronms; bracts narrow, acuminate, scabrous on the 

 keel, 3-nerved, nearly reaching to the apex of the nearest bractlet; internodes 

 of the rachilla short, nearly smooth; bractlet 5 to 6 lines long, hirsute all 

 over; teeth subulate; awn stout, twisted below, then bent outwards, 6 to 8 

 lines long. — (Bromus barbatoides Beal.) 



Near thickets on hillsides, San Francisco; also reported from Oakland. 

 Mar.-June. 



2. T. nutkaense (Presl.) Scrib. & Merrill. Nodding Oat-grass. Peren- 

 nial; stems 2 to 3 ft. high, slender, in tufts; leaf-blades 6 to 9 in. long, iy 2 

 to 6 lines wide, varying from sub-glabrous to pilose ; panicle 4 to 10 in. 

 long, at first narrow and slender, becoming very open, drooping above; branches 

 in remote whorls, at first erect, then drooping, long, capillary, scabrous, bearing 

 2 to 3 or rarely 4 spikelets above the middle; spikelets 3 to 6 lines long, 1 line 

 wide; bracts very unequal, the lower narrow, subulate; upper about y>> longer, 

 broad, 3-nerved, obtuse and mucronate; rachilla clothed with long, silky hairs, 

 internodes 1 to l 1 /* lines long, the lowest shorter than the others, the terminal 

 bearing an empty bractlet or a long, slender awn; bractlet 2 to 3 lines long, 

 smooth or scabrid; teeth long and subulate; awn slender, about twice the 

 length of its bractlet. — (T. cernuum Trin.) 



Shady thickets in northern and middle California. Mar.-June. 



3. T. canescens Buckl. Silvery Oat-grass. Perennial; stems 1 to 4 ft. 

 high, stout, erect ; sheaths varying from glabrous to densely pubescent ; 

 ligule 1% lines long, acute; panicle 5 to 12 in. long, iy 2 to 2y 2 lines wide, 

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

 branches erect, somewhat crowded, all bat the longest bearing spikelets to the 

 base, longest 2% in. long; spikelets about 4 lines long, narrow, 2 to 3-flowered; 

 lower bract narrow, acute, about V± shorter than the broad upper one; bract- 

 lets not spreading nor very remote, imbricate, 3 to 4 lines long, narrow r , 

 minutely puberulent, long subulate-pointed; awn stout, about twice the length 

 of its bractlet. 



Dry open ground or open woods and thickets: Coast Ranges northward to 

 Oregon and in the Sierra Nevada. 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 Blender, 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 perfecl flowers. Bract- 

 let rounded on the hack, the apes (in ours) shortly 2-lid, the back bearing a 

 stout awn, mostly geniculate and twisted below; palea narrow, 2-dentate or 2-lid, 

 2-keeled. Scales 2-fid. Stamens :i; anthers sub-basinxed. Ovary and achene 



