GRAMINE.E. (GRASS FAMILY.) 619 



71. AGROPYRUM, Beauv. Couch Grass. 



Spikelets 3 - many-flowered, compressed, the side applied to the rachis. 

 Glumes 2, in all the spikelets. Otherwise like the preceding. 



1. A. repens, Beauv. Culms erect from creeping rootstocks; spikes 

 erect, spikelets 4 - 8-flowered ; awns short and straight, or none. — Cultivated 

 fields. Introduced. 



2. A. caninum, R- & S. Rootstocks none; spikes nodding; spikelets 

 3 - 5-flowered ; awns spreading, twice as long as the florets. — Sparingly- 

 introduced. 



72. HORDEUM, L. Barley. 



Spikelets 3 at each juint of the terminal spike, the lateral ones imperfect, 

 the middle one 1-flowered, with a rudiment at the base of the palet. Glumes 2 

 before each spikelet, unequal, awned. Flowering glume awned. ~ Stamens 3. 

 Grain adhering to the palet. 



1. H. pratense, Huds. Annual, 6'- 18' high; upper sheath dilated; 

 lateral spikelets short-pedicelled, awuless, the middle one loug-awned. — Road- 

 sides and waste ground. Introduced. 



73. ELYMUS, L. Lyme Grass. 



Coarse flat-leaved perennial grasses, with rigid erect culms, bearing a single 

 spike of 2-7-flowered spikelets, arranged 2-4 in a cluster at each joint of the 

 flexuous rachis. Glumes 2, placed side by side before the spikelets, coriaceous, 

 unequal-sided, mostly awned. Florets of the same texture as the glumes, the 

 glume convex on the back, tapering into a rigid awn, the palet enclosing the 

 linear hairy-tipped grain. Stamens 3. Stigmas 2. 



1. E. Virginicus, L. Spike dense, erect (3' long), the base usually in- 

 cluded in the dilated sheath of the uppermost leaf ; spikelets 2-3 in a cluster, 

 2 - 3-flowered, smoothish, short-awned ; glixmes lanceolate, strongly nerved. — 

 River banks. July - August. — Culms 2° - 3*^ high. Leaves rough. Sheaths 

 smooth. 



2. E. Striatus, Wilkl. Spike dense, erect or slightly nodding (3' -5' 

 long), long-peduncled; spikelets 2-3 in a cluster, 1 -3-flowered, hairy, long- 

 awned ; glumes linear-subulate, long-awned, much longer than the flowers. — 

 Rocky woods and banks in the upper districts. July - Sept. — Culms slender, 

 2° high. Leaves and sheaths smooth or pubescent. 



3. E. Canadensis, L. Spike long (6' or more), erect or nodding, ex- 

 serted ; spikelets in pairs, 5 - 6-flowered ; glumes and paleje more or less 

 rough-hairy, long-awned. — River banks, mountains of Georgia and Tennessee. 



• — Culms 3° -4° liigh. Leaves broadly liuear. 



74. ASPRELLA, Willd. Bottle-brush. 



Spikelets 2 - 3 on each joint of the rachis, raised on a short and thick stalk 

 Glumes none, or a single awn-like rudiment. Otherwise as in Elymus. 



