GRASS FAMILY 



245 



75. HORDEUM L. Sp. PI. 84. 1753. 



Spikelets 1-flowcred, 3 (sometimes 2) together at each node of the articuhitc rachis 

 (continuous in H. itilgarc), the middle one sessile or subsessile, the lateral ones pediceled; 

 rachilla disarticulating above the glumes and, in tlie central spikelet. prolonged behind the 

 palea as a bristle, this sometimes bearing a rudimentary floret ; lateral spikelets usually 

 imperfect, sometimes reduced to bristles; glumes narrow, often sulnilate and awned, rigid, 

 standing in front of the spikelet; lemmas rounded on the back, 5-nerved, usually ol)scurely 

 so, tapering into a usually long awn. Annual or perennial low or moderately tall grasses 

 with flat blades and dense terminal cylindrical spikes. [An ancient Latin name for barley.] 

 Species about 20 in the temperate regions of both hemisiiheres. Type species, Hordenm vulgarc L. 



Plants annual. 



Glumes, or some of them, ciliate. 

 Glumes not ciliate. 



Glumes ot the fertile spikelet dilated above the middle. 

 Glumes not dilated. 



Glumes glabrous or nearly so. 

 Glumes very scabrous. 

 Plants perennial. 



Awns 2-S cm. long. 

 Awns 4-5 cm. long. 

 Awns 2—3 cm. long. 

 Awns not over 1 cm. long. 



Spikes rather stout, the central florets rather prominent on each side of the spike; culms 50-100 cm 

 „ t.a"- , J , , . 7. W. boreale. 



bpikes slender, the awns obscuring the fertile central florets; culms mostly less than 50 cm. tall. 



8. H. nodosum. 



1. H. nuirinum. 



2. H. pHsilhnii. 



3. H. gnssoncannm. 



4. H. del>ressum. 



5. H. jitbatum. 



6. H. caespitosnm. 



1. Hordeum murinum L. 

 Wall Barley. Fig. 581. 



Hordeum murinum L. Sp. PI. 85. 1753. 



Annual; culius bushy-branched, spreading; sheaths 

 and blades smooth ; spike 5-7 cm. long, often partially 

 enclosed by the uppermost inflated sheath ; glumes of 

 the central spikelet narrowly spindle-form, 3-nerved, 

 long-ciliate on both margins, the nerves scabrous ; 

 awn about 2.5 cm. long; glumes of the lateral spike- 

 lets unlike, the inner similar to the central, the outer 

 setaceous, not ciliate; lemmas all broad, 8-10 min. long, 

 the awns somewhat exceeding those of the glumes. 



Fields, waste places, and open ground, introduced from 

 Europe. British Columbia to Lower California, east to Idaho 

 and Xew Mexico, rare in the eastern States. Apr.-Tuly. Type 

 locality, European. Also called Wild Barley and Foxtail. 



2. Hordeum pusillum Nutt. 

 Little Barley. Fig. 582. 



Hordeum pusillum Nutt. Gen. PI. 1: 87. 1818. 



Annual; culms 10-35 cm. tall; blades erect, flat; 

 spike erect, 2.-7 cm. long, 10-14 mm. wide; lateral 

 pair of spikelets abortive, the first glume of each 

 and both glumes of the fertile spikelet dilated 

 above the base, attenuate into a slender awn 8-15 

 mm. long; glumes very scabrous; lemma of central 

 spikelet awned, of lateral spikelets awn-pointed. 



Plains and open, especially alkaline ground; southern 

 California (San Diego, Baker, Orcutt: Santa Catalina Isl- 



^r ', ^^^.■^'' "^?*' ^° *^*'"°- Apr.-June. Type locality: plains 

 01 the Missouri. 



