228 



GRAMINEAE. 



Agropyron caninum (L.) R. & S. Awned Wheat-grass. Fibrous-rooted 

 Wheat-grass. (Fig. 528.) 



Triticum caninum L. Sp. PI. 86. 1753. 

 Agropyrum caninum R. & S. Syst. 2: 756. 1817. 



Agropvrum nnilaterale Cassidy, Bull. Colo. Agric. 

 Exp. Sta. 12: 63. 1890. 



Culms i-3 tall, erect, simple, smooth and gl 

 brous. Sheaths usually shorter than the iuter- 

 nodes, smooth, the lower sometimes pubescent; 

 ligule short; leaves 3'-9 x long, i // -3 // wide, smooth 

 beneath, rough above; spike 3 '-8' in length, 

 sometimes one-sided, often nodding at the top; 

 spikelets 3-6 flowered; empty scales 4^ // -6 // long; 

 3~5-nerved, acuminate, awn-pointed or bearing an 

 awn i // -3 // long; flowering scales 4 // ~5 // long, usu- 

 ally scabrous toward the apex, acuminate into an 

 awn sometimes twice their own length. 



New Brunswick to British Columbia, south to North 

 Carolina. Tennessee and Colorado. Also in Europe 

 and Asia. Native northward; southward locally natu- 

 ralized from Europe. Juty-Aug. 



89. HORDEUM L. Sp. PI. 84. 1753. 



Annual or perennial grasses, with flat leaves and terminal cylindric spikes. Spikelets 

 i-flowered, usually in 3's at each joint of the rachis, the lateral generally short-stalked and 

 imperfect; rachilla produced beyond the flower, the lower empty scales often reduced to 

 awns and forming an apparent involucre around the spikelets. Empty scales rigid; flower- 

 ing 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 16 species, widely distributed in both hemispheres. 



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

 Awn of the flowering scale 1 A' 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. Pjisillum. 



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



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



i. Hordeum nodosum L. Meadow Barley. (Fig. 529.) 



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 #" long, truncate; 

 leaves i Yt'-s' long, i"-$" wide, flat, rough; spike 

 i'-3#' i Q length; spikelets usually in 3's, the central 

 one containing a palet and perfect flower, the lateral 

 enclosing a staminatc or rudimentary flower, or a 

 palet only; empty scales of each cluster awn-like; 

 flowering scale of the central spikclet 3"-4" long 

 exclusive of the awn, which is 3 // -6 // long, the cor- 

 responding scale in the lateral spikelets much 

 smaller and short-stalked. 



In im-adows and \vasU- places, Indiana to Minnesota 

 British Colombia and Alaska, south to Texas and 

 California. Also in Europe and Asia. June-July. 



