684 POACE.^l. 



€. TioviNM: Hack. Ligulc very short, truncate, throat of 

 sheath o/tni falcate-aurirnhte, hhules usuallif all flat, 

 rarely sii/>ronvohite. Ovary ohovoid, glabrous. Grain 

 often adherent to ylnnie and 2>alea. 



a. Arctic; jfrasses. small 5 



a. Not arctic, larger (b) 



b. Ujiper ligulc 1-2-5 mm. long, floral glume 6-8 



mm. long G 



b. Upper ligulc 1 mm. long, or less (c) 



c. Floral glume 4 mm. long, coriaceous, obscurely 



nerved 7 



C. Floral glume 5 mm. long, cliartaceous, ob- 

 scurely nerved 8 



c. Floral glume 5-!* mm. long, not eoriaceoiis. . (d) 

 d. Floral glume (5--S nun. long, seabrid, awn 8- 



12 mm. long 



d. Floral glume 8-!) mm. long, scaljrous, sliort 



awned 10 



d. Floral glume 7-8 mm. long, scabrous, sliort 



awned 11 



d. Floral glume G nim. long, S(!al)rous, sliort 



awned 12 



d. Floral glume 0-7 nun. long, scabrid toward 



the apex, rarely awned 13, 14 



d. Floral glume 5-7 mm. long, awn 5-12 mm. 



long 15 



D. Ovix.'i: IFaek. Lirpdc very short, trnncote, itsnally lii- 

 anricnlate, hlades all condnplintte or thosr of the nilm 

 more or less jhitfened. Ovary ohovatc-ohltmy, ylafirons. or 

 the apex rarely thinly hispid. Grain adhering closely to 



Jloral (jlume a)ul palea (e) 



e. Ligule very sliort, symmetrically biauriculate, blades 

 more tlian 2 cm. long, all conduplicate. in transverse 

 section, oval to oblong or cuueatc, oblong. Ovary 



very smooth (ni; 



m. Leaves oi" culm 2-3 16 



