160 GRAMINEAB 



12,000 feet altitude: Mt. Lyell, Hitchcock 3294, 3296, 3300, 3302; Lyell Fork 

 Canon, Hitchcock 3290; Siberian Outpost, Hitchcock 3436, 3451, 3452. The 

 type, from southeastern Oregon, is the only other collection known. 



Kef. POA LEIBEBGII Scribn. U. S. Dept. Agr. Div. Agrost. Bull. 8 : 6. pi. 2. 1897. 



30. P. cottoni Piper. Tufted perennial; culms erect, smooth, scabrous be- 

 low panicle, 1 to 2 feet high ; sheaths smooth or slightly scabrous ; ligule less 

 than 1/2 line long; blades involute, erect, scabrous; panicle long-exserted, 

 oblong, contracted, sometimes almost spike-like, 1 to 2 inches long; spikelets 

 about 3 lines long; glumes broad, smooth, scarcely scabrous on the keel, the 

 first li/2 lines long, the second a little longer; lemmas 2 lines long, smooth or 

 minutely scabrous, not webbed at base, nerves all prominent. 



Rocky woods, and along mountain streams, high Sierra Nevada, north to 

 Washington. 



Locs. Pine Creek, Baker $ Nutting, Davy; Nevada Co., Sonne; Sierra Valley, Lemmon 

 5463; Lake Tahoe, Hitchcock 3154, Seed $ Pendleton 1624; Mt. Lyell, Hitchcock 3298; Fare- 

 well Gap, Hitchcock 3386; Mt. Whitney, Hitchcock 3449. 



Ref. POA COTTONI Piper, Proc. Biol. Soc. Wash. 18: 146. 1905. 



59. GLYCERIA R. Br. 



Spikelets few to many-flowered, subterete or slightly compressed, in narrow 

 or spreading panicles. Glumes unequal, short, obtuse or acute. Lemmas con- 

 vex, firm, with a scarious margin or apex, usually obtuse, awnless, 5 to 9-nerved, 

 the nerves usually prominent. Usually tall aquatic perennials. Species about 

 16, temperate regions of both hemispheres. (Greek glukeros, sweet.) 

 Spikelets linear, over 5 lines long. 



Lemmas about 2^ lines long 1. G. plicata. 



Lemmas about 1% lines long. 



Spikelets about % line wide, green; lemmas smooth or minutely scabrous on the nerves. . . 



2. G. borealis. 

 Spikelets about 1 line wide, purplish tinged; lemmas scabrous on the nerves and somewhat 



so between them 3. G. leptostachya. 



Spikelets ovate or oblong, not over 2!/i> lines long. 

 Lemmas with 5 prominent nerves. 



Panicle ovate or pyramidal, open 4. G. pauciflora. 



Panicle narrow, branches ascending. 5. G. erecta. 



Lemmas with 7 prominent nerves 6. G. elata. 



1. G. plicata Fries. Culms ascending from a decumbent rooting base, rather 

 thick and succulent, 4 to 5 feet tall ; sheaths smooth ; blades l 1 /^ to 5 lines wide, 

 scabrous above ; panicle long and narrow ; glumes very unequal, obtuse, the 

 second 1^/2 lines long; lemmas purple-tinged, broad, obtuse, 2 1 /2 lines long, 

 prominently 7-nerved, with an additional short pair near the margin, very 

 scabrous on the nerves and somewhat so between them ; palea about as long as 

 lemma. 



In shallow water, Mendocino Co. (Sherwood, Davy 5183, Hitchcock 2710; 

 Walker Valley. Davy & Blasdale 5083) ; Oregon to Vancouver Island. 

 Eef . GLYCERIA PLICATA Fries, Mant. 3 : 176. 1842. 



2. G. borealis Batchelder. Culms 2 to 3 feet high, erect from a more or less 

 decumbent and rooting base; sheaths smooth or slightly scabrous, keeled; 

 blades flat or usually folded, scabrous above, erect, l 1 /^ to 2 lines wide; pani- 

 cle long and narrow, the branches and slender pedicels appressed; spikelets 

 narrow, nearly terete, % to % inch long, % line wide, pale, not purple-tinged ; 

 glumes 1-nerved, the first % line, the second 1% lines long; lemmas oblong, 

 2 lines long, 7-nerved, smooth or indistinctly scabrous on the nerves. 



Jepson, Fl. Cal. vol. 1 (Gramineae by Hitchcock, pp. 82-160, Apr. 22, 1912). 



