36 POACEAE. 



Panicum barbipulvinatum Nash. Annual; stems erect or decumbent at 

 the base, 15-50 cm. tall, mostly simple; leaf blades 5-30 cm. long, pubescent; 

 sheaths villous; panicle 10-20 cm. long, the capillary branches solitary or in 

 twos, ascending, branched and spikelet-bearing above the middle; spikelets 

 3 mm. long, ovoid, usually on peduncles as long or longer. 



In dry soil. This species has commonly been confused with the eastern 

 P. capillare L. 



Panicum agrostoides Spreng. Tufted perennial, glabrous or nearly so; 

 stems 40-100 cm. high, branched; leaf blades flat, 5-10 mm. wide; panicles 

 10-30 cm. long with ascending rays bearing densely flowered branchlets mostly 

 on the under side; spikelets 2 mm. long; first glume half the length of the spike- 

 let ;. pedicels bearing a few hairs. 



Sproat Lake, Vancouver Island, Macoun. Not otherwise known in our 

 limits. 



Panicum scribnerianum Nash. Perennial, the stems 10-50 cm. tall, erect 

 or ascending, simple or branched above; stem leaves about 6, the blades lance- 

 olate, 410 cm. long, 615 mm. wide, stiff, ascending, glabrous or sometimes 

 pilose below; sheaths usually pilose, loose; panicles oblong or pyramidal, 

 3-8 cm. long, loose, exserted or the smaller ones included; spikelets turgid, 

 ovoid, 3 mm. long. 



Dry prairies. 



Panicum occidentale Scribn. Stems 20-40 cm. high; sheaths somewhat 

 hairy; blades smooth above, usually hairy beneath; panicle well exserted; 

 spikelets 2 mm. long. 



Rocky banks and prairies. Vancouver Island to Idaho and California. 



Panicum pacificum Hitchc. & Chase. Very similar to P. occidentale, but 

 more pubescent throughout, and the stems more leafy. 

 Vancouver Island to California and Arizona. 



51. HOMALOCENCHRUS. 



Perennials with rough leaves and open panicles; spikelets 

 with but one flower which is perfect; glumes none; lemmas awn- 

 less; grain closely enveloped by the glume. 



Homalocenchrus oryzoides (L.) Poll. Panicle loose, the branches spread- 

 ing; spikelets narrowly oblong, 4-5 mm. long, loosely arranged; lemma his- 

 pidulous, the keel strongly ciliate. 



Lake margins, infrequent in our limits. Seattle, Piper. 



52. PHALARIS. 



Annuals or perennials with spike-like or narrow panicles; 

 spikelets crowded, 1-flowered; glumes 2, about equal, compressed; 

 lemmas 3, the first two much reduced and sterile, the third 

 enclosing a palea and a perfect flower; stamens 3. 



Perennial; panicle branched; glumes wingless. P. arundinacea. 

 Annual; panicle very dense, ovoid; glumes wing- keeled. 



Keel of glumes entire. P. canariensis. 



Keel of glumes toothed. P. minor. 



Phalaris arundinacea L. Reed Canary-grass. Stout tufted perennial, 

 50-200 cm. tall; leaves flat, green, 6-10 mm. wide; panicle erect, 6-15 cm. 

 long; spikelets lanceolate, 5 mm. long. 



Margins of lakes and rivers, in wet ground. 



