384 



OHUER 155. GRAMINE^E. 



5. AGROSTIS, L. BENT GRASS. Spikelets 

 1-flwd. Glumes 2, subequal, awnless, usually 

 longer than the flower. Pales 2, thin, pointless, 

 naked, the lower 3-5-veined, sometimes awned 

 on the bad'', the upper often miaute or wanting. 

 Grain free. Mostly if, caespitous, with slender 

 culms and open panicles. 



AsRtfsTis. Upper pale conspicuous. Panic.'e 



rather dense NOB. 1, 2 



TUICHODIUM. Upper pale minute or wanting. 



Panicle thin, capillary ...(*) 



* Lower palea with a long exserU'd awn on the back No?. 3, 4 



* Lower palca awnless, or bearing a very short awn Nos. 5. 8 



1 A. vulgarlB With. Red-top (a). Culm erect, 1 2f; pan. purple, oblong, with 



short branches ; ligules very short ; lower pale (b) 3-veined, twice longer than thi* 

 upper, nearly awnless. A valuable grass : common. 



2 A. alba L. Florin G. Culm decumbent and rooting at the lower joints, then as 



cending 1 3f, stoloniferous ; lignles long (3 4") : pan. greenish-white, or purplish, 

 contracted ; pale 5-veined. awned or not. Common. 



3 A. can ilia L. Dog's or Brown B. Decumbent and rooting at base, 1 -2f; leaves 



feetaceous-rolled ; pan. brownish ; lower pale and awn exserted. Wet meadows. E. 



<J. nlpiim. Culms low, in tufts, with wide panicles, and twisted awns. Mts. 

 1 \. ararhiioides Ell. Erect, 5 8', pan. $ its length; Ivs. linear-setaceous ; lower 

 pa,e, ", HP awn as fine as a gossamer, twisted, 3 4" long. S. C., Ga., and W. Apr. 



5 A. MCabra Willcl. Rough Hair O. Erect from a decumbent base, 1 2f,- very slen- 



der, all scabrous-hispid ; pan. large, capillary, spkl. purplish, (c, glumes, d, flower). 

 The thin, airy panicles are at length driven before the wind. Fields and pastured. 

 June Aug. 



ft. pet-union*. Panicle pale-green, the branches shorter. In damp shades. 



y. oredphila. Pan. less diffuse; lower pale with a short twisted awn Mts. 



6 A. data Trin. Culms stoutish, simple, erect, 2 3f ; Ivs. broadly linear, pan. pur 



pie, with long suberect whorled branches dense-flowered half their length; gls. If 

 long, lower pale 5-veined, 1". Swamps, N. J. to Ky., and S. Sept., Oct. 



6. SPOROBOLUS, Br. DROP-SEED GRASS. Spikelets 

 1-flwd. Gls. 2, the lower smaller. Fls. sessile. Pales 2, 

 awnless, usually longer than the glumes. Sta. 2 or 3. Grain 

 deciduous, free. U Tough, wiry, with rolled rigid leaves 

 nnd contracted panicles often half-enclosed in the sheath. 



4 VIUA. Grain (caryopsis) linear. Glumes and pales all 



sub-equal. Panicle contracted. . Nos 18 



1 SroR^BOLDS. Grain oval or globous, its pericarp often 

 loose on the seed. . .(a) 



a Glumes very unequal, one of them as long as the purplish pales Nos. 4-6 



a Glumes equal or unequal, both shorter than the pales. Sheaths beardless., .(b) 

 b Panicle contracted, spikeform, sheathed or exserted. Lvs. involute. . .Nos. 7, 8 

 b Panicle capillary, open. Often a 2d flower or rudiment. Lvs. flat. . .Nos. 9, 1C 

 1 S. vagiiiieflorus Torr. (a.) Culms in tufts, simple, ascending, 61-2' ; Ivs- *-4' ; 

 panicles lateral and terminal, mostly concealed in the tumid sheaths: grain } s-iorfi 

 than the 2" pales. Dry gravel. More common W. and S. 



