POACEAE. 23 



approximate at the summit of the culm. Glumes 4 or 3, 

 the innermost one chartaceous, subtending a palea of 

 similar texture and a perfect flower. Stamens 3. Stig- 

 mas plumose. 



1. D. sanguinalis (L.) Scop. Culms erect or decumbent, often 

 rooting at the lower nodes, 3-9 dm. long, smooth; sheaths glabrous 

 or pubescent; leaves 5-15 cm. long, 4-8 mm. wide, acuminate, 

 glabrous or pubescent; spikes 3-10, narrowly linear, 4-15 cm. long, 

 digitate at the summit of the culms; rachis fiat, winged; spikelets 

 2.5-3 mm. long, in pairs, 1 sessile or nearly so, lanceolate; first 

 glume minute, second a half to a third as long as the spikelet. {Pani- 

 cum sanguinale L.) 



Common along irrigating ditches and in neglected orchards and 

 gardens. 



5. PANICUM L. Panic-grass. 



Annual or perennial grasses, varying greatly in habit 

 and inflorescence. Spikelets 1-2-flowered, when 2-flow- 

 ered the lower one staminate only. Glumes 4, the 3 

 lower membranous, empty or the third with a staminate 

 flower; the fourth chartaceous, shining, enclosing a palea 

 of similar texture and a perfect flower. Awns com- 

 monly wanting. Stamens 3. Styles distinct; stigmas 

 plumose. Grain free, enclosed in the hardened fruiting 

 glume and palea. 



Awns present. 1. P. crus-galli. 

 Awns wanting. 



Sheaths glabrous. 2. P. colonum. 

 Sheaths pubescent. 



Annual; panicle 20 cm. long or more. 3. P. capillare. 



Perennial; panicle about 5 cm. long. 4. P. pacificum. 



1. P. crus-galli L. Culms 3-8 dm. high, usually branching 

 at base; sheaths smooth; leaves 1-5 dm. long, 3-12 mm. wide, 

 smooth or scabrous; panicle composed of 5-15 sessile mostly erect 

 or ascending branches; spikelets ovate, green or purple, densely 

 crowded in 2-4 rows on one side of the rachis; second and third 

 glumes about 3 -mm. long, scabrous or hispid, the third glume more 

 or less awned, empty, the fourth ovate abruptly pointed. 



Frequent in neglected orchards and gardens and in waste places. 



2. P. colonum L. Culms tufted, smooth, 2-6 dm. high, often 

 decumbent and rooting at the lower nodes; sheaths compressed, 

 usually crowded; ligule wanting; leaves fiat, 3-15 cm. long, 2-8 

 mm. wide; panicles composed of 3-18, 1-sided more or less spreading 

 dense branches, these 1-3 cm. long, spikelets single, or in 2's or 3's 

 in 2 rows on one side of the hispidulous triangular rachis, obovate, 

 pointed; first glume about half as long as the spikelet, 3-nerved, the 



