1. Puccinellia Parishii Hitchc. 



Annual; culms 3-10 cm. tall; blades flat to subinvolute, less than 1 mm. wide; 

 panicle narrow, few-flowered, 1^ cm. long; spikelets 3- to 6-flowered, 3-5 mm. 

 long; lemmas about 2 mm. long, obtuse to truncate, scarious and somewhat erose 

 at the tip, pubescent on the mid and lateral nerves nearly to the apex and on 

 the intermediate nerves about half way. 



In marshy ground in N. M. (Taos Co.) and Ariz. (Navajo and Coconino cos.); 

 also s. Calif. 



2. Puccinellia distans (L.) Pari. 



Perennial; culms erect or decumbent at base, 2-4 dm. tall, sometimes taller; 

 blades flat or more or less involute, mostly 2-4 mm. wide; panicle pyramidal, 

 loose, 5-15 cm. long, the branches fascicled, rather distant, the lower spreading 

 or finally reflexed, the longer ones naked half their length or more; spikelets 

 4- to 6-flowered, 4-5 mm. long; glumes 1-2 mm. long; lemmas rather thin, 

 obtuse or truncate, 1.5-2 mm. long, with a few short hairs at base; anthers about 

 0.8 mm. long. 



In wet meadows, marshes and wet more or less alkaline soils, in N. M. (San 

 Juan, Rio Arriba and Taos cos.); Que. to B.C., s. to Md., Mich., Wise, and 

 N.D., s. to N.M. and Calif. 



3. Puccinellia Nuttalliana (Schult.) Hitchc. 



Perennial; culms usually erect, slender, rather stiff and firm at base, mostly 

 3-6 (-10) dm. tall; blades 1-3 mm. wide, flat or becoming involute; panicle 

 pyramidal, open, mostly 1-2 dm. long, the distant scabrous branches fascicled, 

 spreading and naked below, as much as 1 dm. long; spikelets 3- to 6-flowered, 

 4-7 mm. long, the florets rather distant, the rachilla often exposed; pedicels 

 scabrous; glumes 1.5-2 mm. long; lemmas 2-3 mm. long, rather narrow, some- 

 what narrowed into an obtuse apex; anthers about 0.7 mm. long. P. airoides 

 (Nutt.) Wats. & Coult. 



In wet usually alkaline soils, in N. M. (San Juan and San Miguel cos.) and 

 Ariz. (Apache and Coconino cos.); Wise, to B.C., s. to Kan., N. M., Ariz, and 

 Calif. 



5. Glyceria R. Br. Manna-grass 



Perennials, tufted or subrhizomatous, culms simple; ligule a hyaline scale; 

 blades flat, thin; panicles open; spikelets turgid or only slightly laterally com- 

 pressed, 3- to 14-flowered; all flowers perfect or the terminal one usually abortive 

 or rudimentary; glumes scarious to hyaline, the first usually shorter, acutish and 

 1 -nerved, the second obtuse, almost equaling the lowest lemma and obscurely 

 3-nerved; rachilla eventually abscising at the lower part of each node; lemmas 

 firm to membranous, green, broadly ovate or obovate, usually blunt and scarious- 

 margined apically, usually awnless, 7-nerved, the nerves not converging to the 

 apex but terminating severally near the distal margin. 



About 40 species, cosmopolitan in distribution. 



1. Spikelets linear, nearly terete, usually 1 cm. long or more, appressed on short 

 pedicels; panicles narrow, erect (2) 



1. Spikelets ovate to oblong, more or less compressed, usually not more than 



5 mm. long; panicles usually nodding (4) 



2(1). Lemmas glabrous between the slightly scabrous nerves 1. G. borealis. 



2. Lemmas scaberulous or hirtellous between the usually distinctly scabrous 



nerves (3) 



3(2). Lemmas about 3 mm. long, broadly rounded at the apex.. ..2, G. arkansana. 



3. Lemmas about 4 mm. long, slightly narrowed at apex 3. G. septentrionalis. 



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