CLASS III. ORDER III. 47 



a long, smooth, flexuous rachis or receptacle, to the two sides of 

 which the spikelets are fixed, alternately, and at some distance 

 from each other. Calyx sessile, of one valve, containing a flat 

 ovate, acute sharp edged spikelet of close lanceolate florets. — 

 May, June. — Perennial. — Introduced, rare. 



51. TRITICUM. 

 Triticcm repens. L. Couch grass. 



Calyx subulate, many nerved, five flo\vered ; florets 

 sharp pointed ; leaves flat; root creeping. Sm. 



Syn. Agropyron repens. Beauv. 



This grass has a long, creeping root, penetrating deeply into 

 the earth, and very tenacious of life, which renders it a trouble- 

 some weed in cultivated grounds. Stem about two feet high. 

 Leaves spreading, flat, rough on the edge and upper surface. 

 Stem ending in a flexuous receptacle, bearing two rows of alter- 

 nate, sessile spikelets, more numerous and crowded, than in Lo- 

 lium perenne. Glumes all lanceolate, subulate, and acuminate. 

 — Flowers all summer. — Perennial. 



52. ELYMUS. 

 Elymus Virginicus L. Lyme grass. 



Spike erect; involucres striated, four or six leaved ; 

 spikelets two or three together, each containing two 

 or three flowers, mostly smooth. 



The large erect spikes of this grass resemble at a distance 

 heads of barley. The stem is round and smooth. Leaves 

 smooth, somewhat rough on the margin. The stem ends in a 

 compressed, flexuous, toothed receptacle ; each tooth supporting 

 an involucre of four or six striated, rough, lanceolate glumes, 

 ending in short awns. Each involucre contains two or three 

 flowers. Calyx lanceolate with a straight terminal awn. — 

 Marshes. — July. — Perennial. 



Elymus striatus. Willd. Striated Lyme grass. 



Spike erect ; involucre four leaved, nerved ; spike- 

 lets two together, each one or two flowered, hispid. 



