MANUAL OF THE GRASSES OF THE UNITED STATES 



57 



Figure 55.— Distribution of 

 Bromus tectorum. 



spreading or flexuous; spikelets narrow, 1.5 to 2 cm long, 5- to 7- 

 flowered; glumes lanceolate, acuminate, the first mostly 1 -nerved, 8 to 

 10 mm long, the second mostly 3-nerved, 12 to 16 mm long; lemmas 

 5-nerved, 12 to 14 mm long, pubescent, acumi- 

 nate, with narrow teeth 2 to 3 mm long, the 

 teeth aristate; awn 1.5 to 2 cm long, twisted 

 below, bent below the middle and strongly 

 divaricate when old. O (Including B. trinii 

 var . pallidiflorus Desv.) — Dry plains and rocky 

 or wooded slopes, Oregon, California, and 

 Baja California, rarely eastward to Colorado; 

 introduced from Chile (fig. 57). 



Bromus trinii var. excelsus Shear. Differing in having larger 

 spikelets, 7-nerved lemmas, and divaricate but not twisted or bent 

 awns; teeth of the lemma acuminate, but not aristate. O —A little- 

 known form from the Panamint 

 Mountains, Calif. 



The genus Brachypodium Beauv. is 

 represented in the United States by 

 one species found only on ballast, and 

 another occasionally cultivated. The 

 genus is placed in Festuceae though 

 it resembles Agropyron, differing from 

 it in having short-pediceled spikelets. 

 Lemmas rounded on the back. 

 Brachypodium distachyon (L.) 

 Beauv. (Bromus distachyos L.) is an 

 annual 10 to 20 cm tall, with short 

 flat blades and an erect stiff raceme of 

 1 to few appressed almost sessile awned 

 spikelets. O — On ballast, New Jer- 

 sey (Camden) and Oregon (Portland). 

 Adventive from Europe. Brachy- 

 podium sylvaticum (Huds.) Beauv. 



is a perennial with usually several spikelets in a raceme. 01 — Occasionally 



cultivated for ornament. Europe. 



3. FESTUCA L. Fescue 



Figure 56.— Bromus trinii, X 1. (Eastwood, Calif.) 



Spikelets few- to several-flowered (rarely 1 -flowered in some of the 

 spikelets of a panicle), the rachilla disarticulating above the glumes 

 and between the florets, the uppermost floret 

 reduced; glumes narrow, acute, unequal, the 

 first sometimes very small ; lemmas rounded on 

 the back, membranaceous or somewhat indu- 

 rate, 5-nerved, the nerves often obscure, acute 

 or rarely obtuse, awned from the tip, or 

 rarely from a minutely bifid apex, sometimes 

 awnless. Low or rather tall annuals or peren- 

 nials, the spikelets in narrow or open panicles. 

 The blades are sometimes somewhat auriculate as in the Hordeae. 

 Standard species, Festuca ovina. Name from Festuca, an old Latin 

 name for a weedy grass. 



Many of the perennial species of fescue are important forage grasses 

 in the grazing regions of the West. Festuca arizonica, Arizona fescue, 



Figure 57.— Distribution of 



Bromus trinii. 



