TlIK (iRASSKS OF Tknnkhskk. 75 



3. Empty glumes equal, awu very slender, tlexnose, minutely 

 pubescent, several limes lonj4:er than the spikelet . . . 



8. A. ARACHNOIDES. 



3. Empty glumes unequal, awn stouter, geniculate, not pubes- 



cent, about twice as lung as the spikelet 4 



4. Culms 6 to 12 inches high, panicle 2 to 3 inches long, plants 



alpine 6. A. ruhra Amkricana. 



4. Culms 12 to 24 inches, panicle 4 to 6 inches long, plants not 



alpine 7- A. canina. 



5. Radical leaves involute filiform; panicle branches long and 



widely spreading: spikelets crowded near the extremi- 

 ties of the branches; flowering one- third shorter than 

 the empty glumes; flowering in April . . 5. A. scabra. 



5. Radical leaves flat, spikelets more scattered on more or 



less divergent pedicels; flowering late in summer or early 

 autumn ^ 



6. Culms weak and decumbent below, leaves numerous, 3 to 



4 inches long, thin and widely spreading, spikelets less 

 than a line long on diverging pedicels . 3. A. perennans. 



6. Culms erect, or geniculate only at the lower nodes, spikelets 



I line long or more 7 



7. Culms slender, sheaths smooth, flowering glume about one- 



fourth shorter than the thin empty ones 



2. A. INTERMEDIA. 



7. Culms stouter, sheaths scabrous or conspicuously striate, 



flowering glumes nearly equalling the firmer empty ones. S 



8. Leaves erect, with rigid involute tips, panicle-branches 



ascending, naked below, spikelets appressed and some- 

 what crowded near the ends of the branches 1. A. ei.ata. 

 8. Leaves long and spreading, panicle elongated (6 to 1 2 inches) 

 the numerous, compound and flexuose branches finally 



widely spreading, spikelets not crowded 



4. A. Nov.E-ANGLI.t. 



I. Agrostis elata Trin. 



Plate XXIV. Figure 96. 



An erect, rather stout and rigid perennial, about two feet high. 

 Sheaths scabrous, especially near the top; ligule two to four lines 

 long; leaf blade rather firm in texture, erect, one to three lines 

 wide, four 10 seven inches long, gradually tapering to the atten- 

 uate and rigid involute tips, scabrous. Panicle six to twelve 

 inches long, with rigid, slightly spreading branches; primarv 

 branches three to ten at a node, verticillately-branched above the 

 middle; the ultimate branches flower-bearing above the middle,, 

 the spikelets usually crowded. Empty glumes nearly equal, lan- 

 ceolate, acute, about one and one half lines long, minutely pubes- 

 cent, thick in texture, the keels hispid scabrous, at least toward 

 the tips. Flowering glume a little shorter, minutely hispid on the 

 nerves. Thickets, open woods, usually in somewhat sandy soil- 

 August to October. Common. 



