204 GRASSES OF IOWA. 



5. BOUTELOUA. 



Bouteloua Lag. Var. Cienc. y. Litt. 2: 141. 1805. Bentham & 

 Hooker. Gen. PI. 3: 1168. Scribner. Bull. U. S. Dept. Agrl. Div. Agros. 

 20: 106. /. 80. (Rev. ed.) 



Chondrosium Endlicher. Gen. PI. 94. 



Chondrosium Desvx Bull. Philom. 2: 188. 1813. Hackel in Engler and 

 Prantl. Nat. Pflanz. Fam II. 2: 59. /. 70. 



Spikelets crowded and closely sessile, in 2 rows on one side of a 

 flattened rachis. comprising one perfect flower below, and one or more 

 sterile (mostly neutral) or rudimentary flowers. Glumes convex-keeled, 

 the lower one shorter. Perfect flower with the 3-nerved glume 3-toothed 

 or cleft at the apex, the 2-nerved palet 2-toothed, the teeth, at least of 

 the former, pointed or subulate-awned. Stamens 3 ; anthers orange 

 colored or red. Rudimentary flowers mostly 1 to 3-awned. Spikelets 

 solitary, racemed or spiked ; the rachis somewhat extended beyond the 

 spikelets. ( Named for Claudius Bouteloua, a Spanish writer upon flori- 

 culture and agriculture.) 



About 25 species, chiefly American. Largely developed west of the 

 Missouri river, in southwestern United States. A few species of wider 

 distribution. Bentham & Hooker recognize 25 species; Hackel in 

 Engler and Prantl, 30; Scribner, 30; Heller catalogues 18 species for 

 the United States. There are 3 in Wisconsin, Minnesota Valley 3, 

 Iowa 3, Alabama 1, Tennessee 1, New York 1, New Jersey 1, Rocky 

 Mountains 5, California 3 to 4, western Texas 17, Mexico and Ari- 

 zona 23, Canada 3. 



KEY TO THE SPECIES OF BOUTELOUA. 



Spikes of few spikelets, short, numerous, in a long, one sided raceme 

 {Atheropogon) B. curtipendula. x . 



Spikes pectinate, of many spikelets, solitary, or a few in a raceme. 



— Chondrosium . 



Pedicel of rudimentary flower with a tuft of long hairs at summit. 



--B. oligostachya. 2 . 



Pedicel of rudimentary flower glabrous B. hirsuta. 3 . 



