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 joint 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, awued. Flowering giurne awued. Stamens 3. 

 Grain adhering to the palet. 



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

 lateral spikelets short-pedicelled, awuless, the middle one loug-awued. 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 ; glumes lanceolate, strongly nerved. 

 River banks. July - August. Culms 2 - 3 high. Leaves rough. Sheaths 

 smooth. 



2. E. Striatus, Willd. 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, loug-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 palece more or less 

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

 Culms 3 -4 high. Leaves broadly linear. 



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 iu Elyraus. 



