POACEAE. 41 



Elymus leckenbyi Piper. Stems stout, erect, 60-80 cm. tall; leaf blades 

 stiff, erect or ascending, 4-12 cm. long, involute, glabrous beneath, strigose 

 above, sharply acuminate; sheaths glabrous, or on sterile shoots ciliate; spike 

 10-15 cm. long, slender, usually erect, long-exserted ; glumes 2, equal, entire, 

 or unequally bifid, subulate, 2.5-3 cm. long; lemma lanceolate, 8-9 mm. long, 

 smooth at base, scabrid above, bifid at apex and tipped with a straight awn, 

 3-4 cm. long. Bars of Snake River at Wawawai. 



63. HORDEUM. Wild Barley. 



Cespitose annuals or perennials with terminal cylindrical 

 spikes; spikelets 1-flowered, usually in threes at each joint of the 

 rachis, the lateral generally short-stalked and imperfect; rachilla 

 produced beyond the flower; lower glumes often reduced to awns 

 and forming an apparent involucre around the spikelets ; glumes 

 rigid ; lemmas rounded on the back, 5-nerved at the apex, awned ; 

 palea scarcely shorter than the lemma; grain usually adherent 

 to the lemma, hairy at the summit. 



Floret of central spikelet pedicelled, its glumes ciliate. H. murinum. 



Floret of central spikelet sessile, its glumes not ciliate. 



Glumes not all subulate, the inner ones obliquely lanceo- 

 late. H. geniculatum. 

 Glumes all alike, subulate. 



Lateral florets long-awned. H. jubatum. 



Lateral florets awnless or short-awned. 



Florets of lateral spikelets neutral. H. nodosum. 



Florets of lateral spikelets perfect. H. boreale. 



Hordeum murinum L. Wall Barley. Stems 15-30 cm. tall; leaf blades 

 2-12 cm. long, 2-6 mm. wide; spikes 5-10 cm. long, thick; spikelets mostly in 

 threes, all stalked; both glumes of the central spikelet and the inner glume of 

 the lateral spikelets ciliate and flattened, bearing awns 20-25 mm. long; outer 

 glumes of lateral spikelets neither flattened nor ciliate; lemma scabrous at the 

 apex, long-awned. A troublesome weed, sparsely introduced. 



Hordeum geniculatum All. Annual, glabrous, 10-30 cm. high; upper 

 sheath inflated; spike cylindrical, green, 2-5 cm. long; lemma 2-2.5 cm. long 

 including the stiff straight awn. Sparingly introduced from Europe. 



Hordeum jubatum L. Squirrel Tail. Annual, tufted, erect, 30-60 cm. 

 high, glabrous or sometimes pubescent; leaf blades flat, becoming involute, 

 the sheaths shorter than the internodes; spike-like panicle pale green or yel- 

 lowish, 7-10 cm. long, readily breaking apart; central spikelet sessile, fertile, 

 the lateral ones peduncled and sterile; glumes all subulate, 3-6 cm. long. In 

 moist places. 



Hordeum nodosum L. Annual or perennial, 30-90 cm. high, erect; leaf 

 blades flat or involute, the sheaths smooth or hairy; spikelike panicle 3-8 cm. 

 long, narrow, usually flexuous, readily separating into joints; central spikelet 

 sessile, fertile, the lateral ones peduncled and sterile; glumes all subulate, 2 

 cm. or less in length. Common in moist ground. 



Hordeum boreale Scribn. & Smith. Similar in every way to H. nodosum 

 except for the perfect lateral florets. It is probably a subspecies at best. 

 In moist ground. 



