774 OBDEU 156.GR AMINES. 



Ivs. lance-linear, flat, clustered, 12' long, 23" wide; "spike solitary, axil- 

 lary, setaceous, about 4-flowered ; paleae awnless ; stig. 2, very long ; fr. reni- 

 form." U Water, S. Car. to Fla. and La (Hale, whose specimens are without 

 fls. or fruit.) (Hydrochloa, Palis. Hydropyrum, Kunth.) 



4. AGROS'TIS, L, BENT GRASS. (Gr. aypof, a field; growing in 

 fields and pastures.) Spikes 1-flowered ; glumes 2, subcqual, awnless, 

 usually longer than the flower ; pales 2, thin, pointless, naked, the lower 

 -'i 5-veined, sometimes awned on the back, the upper often minute or 

 \vanting; grain free. Zf. mostly, and caespitous, with slender culms 

 and an open panicle. 



5 AC.ROSTIS proper. Upper pixlea i to as long as tho lower. Flj. rather dense. . , . .Nos. 1, 2 

 $ TRICIIODIUM. Upper palea minute or wivntini;. 1'anicle thin. (*) 



* Lower palea with a long exscrted awn on the back. .Nos. 8. 4 



* Lowc-r palt IB awnless, or bearing a very short awn.. Nos. 5. 



1 A. vnlgaria With. RED Toi\ DEW GRASS. HERD'S GRASS of the S. State?. 

 Culm erect, 1 2f high ; panicle, purple, oblong, with short, spreading or divari- 

 cate, roughish branches ; Ivs. linear, with very short ligules (sometimes the upper 

 one elongated) ; lower pale twice as large as the upper, and nearly as long as tho 

 lanceolate, acute glumes, mostly awnless. U. S. and Can. A very valuable 

 grass spread over hills, vales and meadows, forming a soft, dense turf. Variable. 

 (A. polymorpha Huds. A. pumila L. A. hispida Willd.) 



2 A. alba L. WHITE BEST. ENGLISH BENT. BONNET GRASS. FLORIN GRASS. 

 Culm decumbent, geniculate, rooting at the lower joints and sending out stolons ; 

 Ivs. linear, smooth, those of the stolons erect and somewhat subulate ; ligules liny, 

 membranous ; panicle dense, narrow and contracted after flowering, greenish white 

 or slightly purplish ; lower pale 5-veined, rarely awned. A common and valuable 

 grass in old fields and drained swamps. It is quite variable ia aspect. Eur. 

 (A. stolonifera L. A decumbens Muhl.) 



13. STRICTA. Lower pale with an awn from its base twice longer than itself. 



(A. stricta Wilid.) 

 }'. DISPAR. SOUTHERN BENT. Larger (2 3f high) in all its parts ; outer pale 



obtusely 3-toothed. Much valued in some parts of the S. States. (A. dis- 



par MX.? Kunth.) 



3 A. canina L. BROWN BENT. DOG'S BENT. Culm rooting at tho lower nodes, 

 slender, somewhat branched, about 2f high ; Ivs. setaceous involute, the upper 

 linear ; panicle diffuse, ovoid, at Isngth brownish, branches rough, diverging, dividing 

 beyond their middle ; glumes Fubequal, shorter than the lower pale which bears 

 a long awn a little below the middle of the bark ; upper pale minute. Wet mead- 

 ows, E. States, rare. Eur. 



/?. ALPINA. Culms low, in Email tufts, with contracted panicles, nearly smooth, 

 purplish ; awn twisted. Mts., N. States, (A. Pickeringii Tuckm.) 



4 A. arachnoides Ell. Culm erect, slender, 5 8' high; paniculate more than 

 half its length ; Ivs. linear-setaceous, 1 3' long ; panicle narrow, brandies capil- 

 lary x floriferous half their length ; glumes green, ovate, acute, '' long, equal ; 

 pale a little shorter, bearing on its back above, the middle a contorted awn 5 or 

 limes longer than itself, and as fine as a gossamer.~-Ca.r. to Ga. (Feay). The awns, 

 from their fineness, can hardly be &ven without a lens. Apr. 



5 A. scabra Willd. ROUGH HAIR GRASS. THIN GRASS. Culms tufted, erect 

 from a decumbent vase, very slendtr, 1- 2f high; Ivs. linear. 3 G' long, rough, 

 the radical involute-setaceous ; ligule oblong, obtuse ; panicle large, with long, 

 capillary, erect, or divergent, scabrous-hispid whorled branches, trichotomously 

 divided near the end; spikelets in terminal clusters, at length purplish; glumes 

 lance-linear, acuminate, scabrous'hispid oh the keel. Fields and pastures, U. S. 

 and Brit. Am. Remarkable for its thin and airy panicles which are at length 

 driven before the wind. Jn., Jl. (T. laxiHorum MX. T. montanum Torr.) 



/?. OREOPHILA. Culm 6- 12' high, simple, panicle less diffuse; pale with a 

 short, twisted awn at its back. Mts. and rocky woods. (A. montana Tuckm.) 



y. PERENNANS. Panicle pale green, branches shorter, floriferous more than 

 half their length. In damp shades. (T. scabrum Muhl. A. scabro, od. 2d.) 



