122 



NEW YORK STATE MUSE DM 



Fertile spikes 2-4' long, pendulous on stalks 1-2' in length or 

 more ; perigynia slightly turgid, scales light brown with long 

 rough awns. 47-48. 



* Stigmas 3 ; achenium triangular. 



t Perigynia biconvex, without a beak. 



Sterile spike single, (rarely 2 or 3) stalked ; fertile spikes 2-4 

 on filiform drooping peduncles, the upper approximate, the lower 

 sometimes distant ; perigynia with a minute point or pointless ; 

 scales blackish-purple or brown. 49-51. 



Spikes 2-5, the upper half or more of the terminal one fertile, 

 sterile below, the others fertile, sessile or short-stalked, erect, green 

 or dark purple ; perigynia smooth or pubescent. 52-54. 



f Perigynia obtusely 3-angled, not compressed, mostly con- 

 tracted at each end ; obtuse or acutish at the apex. 



Sterile spike cylindrical, usually fertile at the apex ; fertile 

 spikes 2-5, linear or cylindrical, densely or loosely flowered, on 

 drooping or suberect partly included peduncles (sessile or short- 

 peduncled and mostly erect in 55) ; bracts leafy, usually surpass- 

 ing the culm; perigynia ovate-oblong or elliptical, nerved, con- 

 tracted at each end, the apex entire or pointed and notched. 

 55-58. 



Sterile spike single (sometimes 2 or 3 in 59), clavate, long- 

 pedu?icled; fertile spikes 2-4, sessile or stalked, erect, mostly dis- 

 tant, or remote (the upper 2 approximate in 60); bracts shorter 

 than the culm or about equaling it in 59 and G3 ; perigynia with 

 a short terete beak in 6 L 59-63. 



Sterile spike short-stalked or sessile; fertile spikes 2-"> 3 cylin- 

 drical or oblong, densely or subdensely flowered, the upper 1 or 2 

 usually sessile at the base of the sterile spike, the others subdis- 

 tant or the lowest remote, stalked and erect (all approximate in 

 64) ; bracts leafy, longer than the culm; perigynia oblong, obovate, 

 or ovate, nerved, without a beak. 64-67. 



t Perigynia with a distinct beak. 



Sterile spike long or short-stalked ; fertile spikes loosely 2-8 

 flowered, the upper 1 or 2 sessiie near the base of the sterile spike, 

 the others distant, sometimes remote, erect, subnexuose ; peri- 

 gynia densely striate-nerved, with a straight or oblique beak; 

 leaves and bracts thin, bright or glaucous green. 68-69. 



