96 



POACEAE 



awned at the apex, keeled to the base. Grain sUghtly compressed laterally, 

 deeply furrowed, free, pubescent at the apex. 



1. S. cereale L. Annual or biennial; stem 1.5-3 m. high, glabrous; leaves 

 scabrous, flat; spike 10-15 cm. long, 4-angled; spikelets 2-flowered; empty glumes 

 subulate; lemma lanceolate, hispidulous-ciliate, 5-nerved, awned. - \Yaste 

 places and old fields; escaped from cultivation. 



75, HORDEUM L. Barley, Squirrel-tail, Foxtail. 



Annuals or rarely perennials, with spicate inflorescence. Spikelets alter- 

 nately in 3's, rarely in2's, at each node of the articulate rachis, sessile or short- 

 pediceled, 1-flowered; flower perfect or in the lateral spikelets often imperfect 

 or rudimentary; rachilla extending beyond the flower as a long slender bristle. 

 Empty glumes 2, awnlike, subulate, or lanceolate, rigid, falling together with the 

 rachilla-joint. Lemma lanceolate, rounded on the back, awned, lobed, or in 

 the lateral spikelets awmless. Palet shorter, 2-kceled. Styles very short, dis- 

 tinct; stigmas plumose. 



Lateral soikelets sessile; annuals. 



Lemma not awnecl, the awns represented by chartaceous lobes. 1. //. aerjiceras. 



Lemma awned. 2. H. tulgare. 



Lateral spikelets stalked; lemma awned. 



Floret of the central spikelet sessile. 



Empty elumes of the central spikelets lanceolate. ^. U. pusUlum. 



Empty glumes of central spikelet not lanceolate. . . 



Inner empty glumes of the lateral spikelets broadened. 4. //. morittmum. 



Empty glumes all setaceous. 

 Lateral floret not awned. 



Plant low. 5-25 cm. high; upper sheaths inflated. 5. H. depressum. 

 Plant taller, 2-6 dm. high; upper sheath nor conspiniously inflated. 

 Lateral floret neutral or staminate; lemma of the central floret 6-8 



ram. long. 6. IL nodosum. 



Lateral floret usually perfect; lemma of the central flower 10 mm. 

 long. 7. //. boreale. 



Lateral florets long-awned. 



Awn 2-3 cm. long. 8. H. caespitosum. 



Awn 4-6 cm. long. 9. H. jubatum. 



Floret of the central spikelets stalked. 



Empty glumes not ciliate. 10. H. montanense. 



Empty glumes or some of them ciliate. 11- H. muriniim- 



1. H. aegiceras (E. Mey.) Royle. Stem 5-7 dm. high; leaf-blades glabrous, 

 1-1.5 cm. broad; spikes about 1 dm. long; spikelets all fertile; empty glumes 

 lance-subulate, strigose; lemma 3-lobed at the apex; lateral lobes lanceolate, 

 acute, divergent; middle lobe ovate, obtuse, slightly hooded. Pearl Barley. 

 Moist waste grounds: cult, and often escaped. Plain — Snbmont, 



2. H, vulgare L. Annual or rarely biennial; stem 5-7 dm. high; leaf-blades 

 broad, flat; ligules obsolete; spikes about 1 dm. long; empty glumes small, sub- 

 ulate, awned; spikelets all hermaphrodite; lemma lanceolate, long-awned, smooth. 

 Barley. Waste places and old fields: sometimes escaped from cultivation. 



3. H. pusillum Nutt. Tufted annual; stem 1-4 dm. high, usually de- 

 cumbent at the base; leaf-blades 1-7 cm. long, 1-4 mm. wide; spike 3-7 cm. long; 

 central spikelets perSfect, the lateral ones imperfect; inner empty glumes of the. 

 lateral spikelets lanceolate, the outer ones subulate, all awned; lemma smooth,, 

 that of the central spikelet 6-8 mm. long, short-awned, those of the lateral 

 spikelets smaller and stalked. Dry soil; Ont.—Ga.— Calif.— B.C. Plain— 

 Submont. Ap-Je. 



4. H. maritimum With. Annual or perennial, branched at the base; 

 branches decumbent below, then ascending, somewhat geniculate, 1-2 dm. high; 

 sheaths loose, pubescent; spike short-exserted or the base included, 3-5 cm. long; 

 empty glumes setaceous except the inner ones of the lateral spikelets, which are 

 sometimes staminate, distinctly amied; otherwise like //. nodosum. Saline soil: 

 Calif.— Wash.— Ida.— Utah. My-Jl. 



6. H^ depressum (Scribn. & Smith) Rydb. Tufted; stem 5-15 cm. high, 

 geniculate at the base, which is covered by the sheaths; leaf-blades 1-3 cm. lung, 

 1-3 mm. wide, auricled at the base, finely pubescent; spikes 2-3 cm. long; lemma 



