MANUAL OF THE GRASSES OF THE UNITED STATES 265 



H. JUBATUM. 

 H. NODOSUM. 



H. MURINUM. 

 H. PUSILLUM. 



Plants perennial; awns slender. 



Central spikelet usually 2-flowered; lateral spikelets short-pedicellate. 



1. H. MONTANBN8E. 



Central spikelet 1-flowered; lateral spikelets long-pedicellate. 

 Awns 2 to 5 cm long 2. 



Awns mostly less than 1 cm long 3. 



Plants annual; awns stouter. 



Glumes, or some of them, ciliate _ 7. 



Glumes not ciliate. 



Glumes of the fertile spikelet dilated above the base 4. 



Glumes not dilated. 



Rachis continuous; floret of central spikelet about 1 cm long. 



8. H. VULGARE. 

 Rachis disarticulating; floret of central spikelet less than 1 cm long. 



Plant freely branching at base; awns stout, rigid, somewhat divergent at 



maturity 5. H. GUSSONEANUM. 



Plant simple or sparingly branching; awns setaceous, softer and less 

 divergent at maturity 6. H. ADSCENDENS. 



1. Hordeum montanense Beal. (Fig. 520.) Culms 60 to 100 cm 

 tall; sheaths glabrous; blades flat, lax, scabrous, 5 to 8 mm wide; spike 

 nodding, 8 to 17 cm long; central 



spikelets usually 2-flowered, with a 

 rudiment of a third floret; lateral 

 spikelets short-pedicellate or nearly 

 sessile, usually well developed; 

 glumes slightly broadened above 

 the base, 1 to 3.5 cm long including 

 awns; lower floret of central spikelet 

 about 8 mm long, the awn 1.5 to 

 3.5 cm long. 91 (H. pammeli 

 Scribn. and Ball.) Prairies, Illi- 

 nois, Iowa, South Dakota, Montana, 



and Wyoming; introduced at St. FIGURE 520. Hordeum montanense, X 1. (V. H. 



Jovite, Quebec (fig. 521). Variable 



and somewhat anomalous; lateral spikelets sometimes with 2 florets. 



Approaches Elymus but lateral spikelets short-pedicellate. 



2. Hordeum jubatum L. FOXTAIL BARLEY. (Fig. 522.) Peren- 

 nial, tufted; culms erect, or decumbent at base, 30 to 60 cm tall; 

 blades 2 to 5 mm wide, scabrous; spike nodding, 5 to 10 cm long, 

 about as wide, soft, pale; lateral spikelets reduced to 1 to 3 spread- 

 ing awns; glumes of perfect spikelet awnlike, 2.5 to 6 cm long, 

 spreading; lemma 6 to 8 mm long with an awn 



as long as the glumes. 9J. Open ground, 

 meadows and waste places, Newfoundland and 

 Labrador to Alaska, south to Maryland, Illi- 

 nois, Missouri, Texas, California, and Mexico; 

 introduced in the Eastern States (fig. 523). A 

 troublesome weed in the Western States, es- 

 pecially in irrigated meadows. HORDEUM 

 JUBATUM var. CAESPITOSUM (Scribn.) Hitchc. 

 BOBTAIL BARLEY. Awns 1.5 to 3 cm long. (H. caespitosum Scribn.) 

 North Dakota to Alaska, south to Kansas and Arizona. 



3. Hordeum nodosum L. MEADOW BARLEY. (Fig. 524.) Peren- 

 nial, tufted; culms erect or sometimes spreading, 10 to 50 cm tall; 

 foliage rather scant, blades flat; spike slender, 2 to 8 cm long; glumes 

 all setaceous, 8 to 15 mm long; lemma of perfect spikelet 7 to 8 mm 

 long, the awn exceeding the glumes; floret of lateral spikelets much 

 reduced. 91 Meadows, moist places, and open ground, Montana. 



FIGURE 521. Distribution of 

 Hordeum montanense. 



