216 



A TEXT-BOOK OF GRASSES 



The spikelets face alternately to the right and left, often apparently 

 in a single row. In Europe this grass is called dog's-tooth, refer- 

 ring to the tooth-shaped old sheaths on the runners, and cock's-foot, 



referring to the digitate inflores- 

 cence. In the British West Indies 

 it is called Bahama-grass. 



243. Chi oris Swartz.—A 

 moderate-sized genus, many 

 annual species of which are 

 weeds in the tropics. On ac- 

 count of the silky spikes they 

 are usually handsome grasses. 

 One species, C. Gayana Kunth, 

 has been introduced in the 

 southern states as a meadow- 

 grass under the name of 

 Rhodes - grass. (See ''Some 

 New Grasses for the South," 

 Yearbook, U. S. Dept. Agr. 

 1912.) 



244. Bouteloua Lag. — 

 Grama-grasses. A genus of 

 about 30 species, all Ameri- 

 can, especially abundant in 

 southwestern United States 

 and on the Mexican plateau. 

 They are important grazing- 



Fio. 47. Bouteloua gracilis. Inflores- ~«r,„„„„ 

 cence, X 1; spikelet, XlO. graSSeS. 



Bouteloua gracilis CEL.B.K.) Lag. {B. oligostachyaTovT.). (Fig. 

 47.) Perennial; culms smooth, tufted, erect, 6 to 18 inches high; 

 sheaths smooth, or the lower somewhat villous, bearing at the 

 throat a tuft of long hairs on each side; Hgule very short; blades 

 mostly basal, flat or usually involute, flexuous or curly, 1 to 2 mm, 

 wide, 2 to 4 inches long, scabrous on the margin; spikes usually 2, 



