228 GRAMINEAE. 
5. Agropyron caninum (L.) R. & S. Awned Wheat-grass. Fibrous-rooted 
Wheat-grass. (Fig. 528.) 
Triticum caninum I,. Sp. Pl. 86. 1753. 
Agropyrum caninum R. & §S. Syst. 2:756. 1817. 
Agropyrum unilaterale Cassidy, Bull. Colo. Agric. 
Exp. Sta. 12:63. 1890 
Culms 1°-3° tall, erect, simple, smooth and gla- 
SSS | brous. Sheaths usually shorter than the inter- 
nodes, smooth, the lower sometimes pubescent; 
DN ligule short; leaves 3-9’ long, 1/’-3’’ wide, smooth 
\ beneath, rough above; spike 3/-8’ in length, 
Y, 5 sometimes one-sided, often nodding at the top; 
/ spikelets 3-6 flowered; empty scales 414’/-6” long; 
3-5-nerved, acuminate, awn-pointed or bearing an 
awn 1//-3/ long; flowering scales 4/’-5’’ long, usu- 
ally scabrous toward the apex, acuminate into an 
| awn sometintes twice their own length. 
ae, 
3 New Brunswick to British Columbia, south to North 
a} Carolina, Tennessee and Colorado. Also in Europe 
and Asia. Native northward; southward locally natu- 
ralized from Europe. July-Aug. 
89. HORDEUM I. Sp. Pl. 84.1753. 
Annual or perennial grasses, with flat leaves and terminal cylindric spikes. Spikelets 
1-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 '%' long or less. 
All the empty scales of each cluster bristle-like. 
Four of the empty scales of each cluster dilated above the base. 
Awn of the flowering scale 1’ long or more. 
Flowering scales, exclusive of awns, about 6’ long. 
. H. nodosum. 
. I, pusillum. 
. HM. jubatum., 
. H. murinum. 
Fone 
1. Hordeum nodosum J,. Meadow Barley. (Fig. 529.) 
Hordeum nodosum I,. Sp. Pl. 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 4%’ long, truncate; 
leaves 114/—-5’ long, 1’/-3’’ wide, flat, rough; spike 
1/-3 44’ in length; spikelets usually in 3’s, the central 
one containing a palet and perfect flower, the lateral 
enclosing a staminate or rudimentary flower, ora 
palet only; empty scales of each cluster awn-like; 
flowering scale of the central spikelet 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 meadows and waste places, Indiana to Minnesota, 
British Columbia and Alaska, south to Texas and 
California. Also in Europe and Asia. June-July. 
