286 



GRAMINEAE. 



Vol. I 



104. HORDEUM (Tourn.) L. Sp. PI. 84. 1753. 



Annual or perennial grasses, with flat leaf-blades and terminal cylindric spikes. Spikelets 

 i-flowered, rarely 2-flowered, usually in 3's at each joint of the rachis, the lateral short- 

 stalked and imperfect, rarely perfect; rachilla produced beyond the flower, the lower empty 

 scales often reduced to awns and forming an apparent involucre around the spikelets. Empty 

 scales rigid ; flowering scales rounded on the back, 5-nerved at the apex, awned ; palet scarcely 

 shorter than the scale, 2-keeled. Stamens 3. Styles very short, distinct. Grain usually 

 adherent to the scale, hairy at the summit. [Latin name for Barley.] 



About 20 species, widely distributed in both hemispheres. Type species : Hordeum vulgare L. 



Lateral spikelets abortive. 



Flowering scales, exclusive of awns, 3"-4" long. 

 Awn of the flowering scale yi' long or less. 



All the empty scales of each cluster bristle-like. I. H. nodosum. 



Four of the empty scales of each cluster dilated above the base. 2. H. pusillum. 



Awn of the flowering scale 1' long or more. 3. H.jubatum. 



Flowering scales, exclusive of awns, about 6" long. 4. H. murinum. 



Lateral spikelets with perfect flowers. 5. H.Pammelii. 



Hordeum nodosum L. 

 Fig. 694. 



Meadow Barley. 



Hordeum nodosum L. Sp. PI. Ed. 2, 126. 1762. 

 Hordeum pratense Huds'. Fl. Angl. Ed. 2, 56. 1762. 



Culms 6'-2° tall, erect, or sometimes decumbent, 

 simple, smooth and glabrous. Sheaths shorter than 

 the internodes ; ligule i" long, truncate ; blades 1 J'-s' 

 long, i"-3' wide, flat, rough; spike i'-3l' in length; 

 'spikelets usually in 3's, the central one containing a 

 palet and perfect flower, the lateral enclosing a 

 staminate or rudimentary flower, or a palet only; 

 empty scales of each cluster awn-like ; flowering 

 scale of the central spikelets z"~A" l° n g exclusive 

 of the awn, which is 3"-6" long, the corresponding 

 scale in the lateral spikelets much smaller and short- 

 stalked. 



In meadows and waste places, Indiana to Minnesota, 

 Alaska, Texas and California. Also in Europe and Asia. 

 June-July. 



2. Hordeum pusillum Nutt. Little Barley. 

 Fig. 695. 



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



Culms 4-15' tall, erect, or decumbent at the base, 

 smooth and glabrous. Sheaths loose, usually shorter 

 than the internodes, smooth and glabrous, the upper 

 often enclosing the base of the spike; ligule very 

 short; blades i-3' long, 4"-a" wide, erect, smooth 

 beneath, rough above; spike 1-3' in length; spikelets 

 usually in 3's, the central one containing a palet and 

 perfect flower, the lateral imperfect; scales awned, 

 the empty ones scabrous, those of the central spike- 

 let and the lower ones of the lateral spikelets dilated 

 above the base; flowering scale smooth, that of the 

 central spikelet 3"-4" long, short-awned, the corre- 

 sponding scale in the lateral spikelets smaller and 

 very short-stalked. 



In dry soil, Indiana to Tennessee, Wyoming, Cali- 

 fornia, Texas and Louisiana ; also sparingly introduced 

 along the coast from Virginia to Florida. June-July. 





