720 GRAMINE.E chjstochloa 



HOMALOCENCHRDS 



large tumid obovate usually hairy spikelets 1}£ lines long. Common in 

 open places, Washington to California. 



* * * ■ Spikelets crowded in 3-4 rows or irregularly on one side of 

 the spike-like branches of the panicle. 



P. Crus-galli L. Sp. 56. Stems stout, 1-4 feet high, often branching 

 at base : sheaths smooth and glabrous : leaves 6-20 inches long, J^-l inch 

 broad, glabrous, smooth or scabrous : panicle composed of 5-15 sessile erect 

 or ascending branches, or the lower branches spreading or reflexed : spike- 

 lets ovate, green or purple, densely crowded, the glumes more or less 

 awned. Common In fields and waste places throughout North America: 

 naturalized from Europe. 



4 CH^ETOCHLOA Scribn. U. S. Dept. Agr. Div. Agros. Bui. 4, 38. 



Mostly annual grasses with erect stems, flat leaves and spike- 

 like panicles. Spikelets 1 -flowered or rarely with a second sta- 

 minate one. Rachella with bristles below the articulation. 

 Spikelets with 4 glumes, the 3 outer membranous, the third often 

 subtending a palet and rarely a staminate flower, the fourth 

 chartaceous, subtending a palet of similar texture and a perfect 

 flower. Stamens 3. Styles distinct, elongated. Stigmas plum- 

 ous. Grain free, enclosed in the glume. 



C. viridis Scribn. 1. c. 39. Setaria viridis Beauv. Stems erect or as- 

 cending, 1-3 feet high, simple or branched: sheaths glabrous : leaves 3-10 

 inches long, 2-6 lines wide: spikes 1-4 inches long: spikelets about a line 

 long, elliptical, much shorter than the upwardly barbed bristles. In waste 

 places and cultivated fields, throughout North America : introduced from 

 Europe. 



Tribe 3 Oryzese Kunth Enum. i, 5. Spikelets usually much 

 compressed laterally, 1-flowered, staminate, pistillate or hermaphro- 

 dite. Empty glumes 2 or none, the flower being subtended by the 

 floral glume and palet alone. Stamens frequently 6. Axis of the 

 inflorescence not articulated. 



5 HOMALOCENCHRUS Mieg. ; Hall Hist. Stirp. Helv. ii, 201. 



Panicle loose, its base Often enclosed by the upper sheath. 

 Spikelets much flattened, more or less crowded and overlapping 

 each other, awnless, 1-flowered. Glumes only one, hard, strongly 

 flattened laterally, fringed on the keel with bristly hairs, 3-nerved. 

 Stamens 1, 3, or 6. Ovary smooth. Styles short. Stigmas plu- 

 mose with branching hairs. Grain flat, enclosed by the glume. 



H. oryzoides Poll. Hist. PI. Palat. i, 52. Stems 2-3 feet high: leaves 

 flat, spreading, 6-8 lines wide, very rough upward : panicle much branched, 

 spreading, 6-8 inches long: spikelets 2j^-3 lines long, pale green : stamens 

 3. In wet places, eastern Oregon to California and the Atlantic States. 



Suborder ii POACEJS R. Br. Verm. Schr. i, 115. 



Spikelets one- to many-flowered, the imperfect or rudimentary 

 flowers if any uppermost. Rachella usually articulated above the 

 empty glumes so that these are persistent. In spikelets wijth 2 or 

 more flowers the rachella is usually articulated below each flow- 

 ering glume. 



