PANICDLARIA GRAMINEA 753 



Palets scarcely shorter than the glumes, rarely longer, 2-keeled. 

 Stamens 2 or 3. Styles distinct, with plumose stigmas. Grain 

 smooth, enclosed in the glume and partly free, or when dry 

 slightly adhering to the palet. 



P. fluitans Kuntze Rev. Gen. PI. 782. G. fluitans It. Br. Stems 

 2-5 feet high, erect: stout, simple smooth, often rooting from the lower nodes: 

 sheaths loose, generally longer than the internodes smooth or rough: ligules 2-3 

 lines long: leaves 5-12 inches long, 2-6 lines wide scabrous: often floating: 

 panicle 9-18 inches long, the lower branches at first appressed, later ascending 

 3-6 inches long: spikelets linear, 7-13-flowered, 4-12 lines long: empty glumes 

 unequal, 1-nerved, the lower acute or obtuse, the upper obtuse or truncate. In 

 water and bogs, California to Alaska and across the continent. 



P. borealis Nash Bull. Torr. Bot. club xxiv, 348. Stems weak, erect, 

 glabrous, 13*2-3 feet high: sheaths loose, longer than the internodes: leaves 4-10 

 inches long, pale green, nearly smooth: panicle lax, 7-15 inches long, the 

 branches single or in pairs usually short and erect: spikelets linear, 5-7 lines 

 long: flowering glumes very thin, l%-2 lines long, 7-nerved, the nerves min- 

 utely hispid. In shallow ponds, eastern Washington to California and the 

 Eastern States. 



P. nervata Kuntze 1. c. G. nervata Trin. Stems slender, erect, 1-3 

 feet high, simple, smooth: sheaths shorter than the internodes, usually more 

 or less rough: ligules % line long, truncate: leaves 6-12 inches long, 2-5 lines 

 wide, acute, smooth beneath, rough above: panicle 3-8 inches long, open, the 

 filiform branches spreading, ascending or often drooping, rarely erect, the lower 

 ones 2-5 inches long: spikelets 3-7 -flowered, 1-1 % lines long: empty glumes 

 obtuse, 1-nerved; flowering glumes about % line long, obtuse or rounded at the 

 apex, with 7 sharp distinct nerves and evident furrows between them. Com- 

 mon in wet places and along streams, California to Alaska and across the 

 continent. 



P. pallida Kuntze 1. c. 783. Pale green, stems 1-3 feet long, assurgent, 

 simple, smooth: sheaths loose, shorter than the intemodes, ligules 2-3 lines long, 

 acute: leaves 2-6 inches long, 1-2 lines wide, smooth beneath, rough above: 

 panicle 2-7 inches long, the branches erect or ascending, often flexuous, 1-2 

 inches long: spikelets 4-8-flowered, 2>-3> lines long: empty glumes unequal, 

 the first 1-nerved, obtuse, shorter than the 3-nerved and truncate second one: 

 flowering glumes 1)^-1 > lines long, truncate and denticulate at the apex, 

 sharply and distinctly 7-nerved, with plain furrows between the nerves. In 

 shallow water, Washington to Indiana and New Brunswick. 



P, panciflora Kuntze 1. c. G. pauciflora Presl Stems etout, 2-4 

 feet long: sheaths nearly smooth, loose, usually longer than the internodes 

 ligules rounded or more often lacerate 2-3 lines long: leaves 6-15 inches long: 

 3-9 lines wide: panicle 5-8 inches long, somewhat contracted and flexuous 

 or at length loose and open, usually purplish, its branches hispid, 4 inches long 

 or less: spikelets 5-7 -flowered, 2-3 lines long: empty glumes less than half as 

 long as the flowering ones, the first ovate, denticulate, near the subacute apex, 

 smooth, 1-nerved % line long; the second erose at the rounded apex, 3-nerved, 

 nearly 1 line long: flowering glumes broadly oblong, erose at the rounded scari- 

 ous apex, hispidulous on the keel, prominently 5-nerved, !-!} lines long: 

 palet oblong, emarginate, slightly pubescent on the 2 keels, nearly equalling 

 the glume In shallow water or wet places, California te Alaska and Colorado. 



P. Americana MacM. Met. Minn. 81. Stems stout, erect, simple, 

 smooth, 3-5 feet high: sheaths loose, smooth or somewhat rough: ligules 1-2 

 lines long, truncate: leaves 7-12 inches long, 3-8 lines wide, usually smooth 

 beneath, rough above: panicle 8-16 inches long, its branches spreading, ascend- 



