68 



GRASSES OF IOWA. 



DESCRIPTION. 



Switch Grass. A stout, 

 erect perennial, 3 to 5 feet 

 (7-12 dm.) high, with strong 

 creeping root stocks, long, 

 flat leaves and ample spread- 

 ing panicle. Culms smooth, 

 terete. Sheaths smooth, cil- 

 iate along the margins above ; 

 ligule very, short, naked, or 

 densely and long pilose; leaf- 

 blade 10 to 24 inches (20-48 

 cm.) lung, 2 to 5 lines (4- 

 IO mm.) wide, scabrous on 

 the margins, sometimes pilose 

 near the base, otherwise 

 smooth, long - acuminate 

 pointed. Panicles 6 to 20 

 inches (12-40 cm.) long; 

 the branches solitary, or sev- 

 eral together, more or less 

 widely spreading, rather 

 rigid, the lower 4 to 10 

 inches (8-20 cm.) long. 

 Spikelets ovate, acuminate, 

 2 to 2-i- lines (2-5 mm.) 

 Long; the acuminate first 



Pro. 47. Panicum mr^um-a, spikeletjb, second S lume about one-half the 

 and third glumes ; c, d, flowering glume. (Div. of length of the spikelct three 

 Agros. TJ. S. Dept. of Agrl. ) 



to five-nerved ; second glume 

 usually longer than the others, five to seven-nerved, as is the third, 

 which has a palea and usually a staminate flower in it> axil; 

 flowering glume smooth and shining, distinctly shorter than the larger 

 inter glumes. Sandy soil, usually alone streams, prairies and about 

 ponds and lakes. July to October. A common grass on the prairies 

 in Iowa, Nebraska and Minnesota. 



