148 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



broad, less than half as long as the spikelet; second glume and the 

 sterile lemma equal or the glume a little shorter; fruit smooth or 

 transversely rugose. 



Plains bristlegrass (S. macrostachya) is Arizona's best forage species. 

 Foxtail-millet (S. italica) , which is grown in the United States for hay, 

 has been cultivated for food by primitive peoples in Europe since 

 prehistoric times. 



Key to the species 

 1. Plants annual (2). 



2. Bristles yellowish or golden, more than 5 below each spikelet; spikelets 3 mm. 

 long; second glume much shorter than the coarsely rugose fertile lemma. 



1. S. LUTESCENS. 



2. Bristles green, 1 to 3 below each spikelet; spikelets 2 to 2.5 mm. long (3). 

 3. Fertile lemma coarsely transverse-rugose; panicle loosely flowered. 



2. S. LIEBMANNI. 



3. Fertile lemma finely crosslined or nearly smooth (4) . 



4. Panicle rather loose, tapering toward the apex 3. S. grisebachii. 



4. Panicle dense, cylindric, scarcely tapering toward the apex. 



4. S. VIRIDIS. 

 1. Plants perennial (5). 



5. Spikelets 3 mm. long; leaf blades villous 5. S. villosissima. 



5. Spikelets 2 to 2.5 mm. long; leaf blades scabrous or pubescent (6). 



6. Panicle spikelike, interrupted, with branches usually not more than 1 cm. 

 long, appressed; blades mostly less than 1 cm. wide. 



6. S. MACROSTACHYA. 



6. Panicle rather loose, the lower branches spreading, up to 3 cm. long; 

 blades flat, up to 1.5 cm. wide 7. S. scheelei. 



1. Setaria lutescens (Weigel) F. T. Hubbard, Rhodora 18: 232. 1916. 



Panicum lutescens Weigel, Observ. Bot. 20. 1772. 

 Chaetochloa glauca (L.) Scribn., U. S. Dept. Agr ., Div. Agrost. 

 Bui. 4: 39. 1897. 



Maricopa County, at Tempe (McLellan and Stitt 549) and Scotts- 

 dale (Peebles 14421). Cultivated ground and waste places, New 

 Brunswick to South Dakota, south to Florida and Texas, occasional 

 from British Columbia to California, Arizona, and New Mexico; 

 introduced from Europe. 



2. Setaria liebmanni Fourn., Mex. PI. 2: 44. 1886. 



West slope of the Baboquivari Mountains, Pima County (Goodding 

 in 1938), open sandy or rocky soil. Arizona to Nicaragua. 



3. Setaria grisebachii Fourn., Mex. PI. 2: 45. 1886. 



Chaetochloa grisebachii var. ampla Scribn. and Merr., U. S. 

 Dept. Agr., Div. Agrost. Bui. 21: 36. 1900. 



Yavapai, Gila, Cochise, Santa Cruz, and Pima Counties, 2,000 to 

 6,000 feet, sandy or stony ground, June to October. Texas to Arizona 

 and Mexico. 



4. Setaria viridis (L.) Beauv., Ess. Agrost, 51, 178. 1812. 



Panicum viride L., Syst. Nat. ed. 10, 2: 870. 1759. 

 Chaetochloa viridis Scribn., U. S. Dept, Agr., Div. Agrost, Bui. 

 4: 39. 1897. 



Apache, Coconino, Pinal, Cochise, and Pima Counties, 2,000 to 8,000 

 feet, fields and open woods. Temperate regions of both hemispheres; 

 introduced from Europe. 



