30 



GRASSES OF IOWA. 



3. ANDROPOGON PROVINCIALIS. 



Andropogon provincialis Lam. Encycl. 1: 376. 1783 Scribner. Grasess 

 of Tenn. Bull. Univ. Term. Agrl Exp. Sta. 7: 22. /. 7. 1891. Bull U S. 

 Dept. Agrl. Div. Agros 7:20. /. 14. 1900. (3d ed.) Beal. Grasses of N. A. 2: 

 55. 1896. 



Andropogon furcatus Muhl. Watson and Coulter. Gray Man. Bot. 

 637. pi. 14. 1890. (6th ed.) Nash in Britton and Brown, 111. PL 1: 102. /. 

 219. 1896 Sub. var. furcatus Hack. D. C. Mon. Phan. 5: 442. 1889. 



DESCRIPTION. 



Blue Stem. A stout perennial, 2 to 5 feet (5-12 dm.) high 



with rather thick racemes, two to five together, terminal on the 



culm and its branches. Culms smooth, terete, often pruinose below the 



nodes, branched above; branches single (rarely two or four together) 



simple. Sheaths smooth or 

 sometimes pilose, those of 

 the sterile shoots usually 

 compressed-keeled ; ligule 

 very short (^ to 1 

 line) truncate; leaf-blade 8 

 inches to 2 feet (2-5 dm.) 

 long, 2 to 5 lines (4- 

 10mm.) wide, tapering into 

 long, setaceous points, mar- 

 gins scabrous, and often 

 fimbriate near the base. 

 Spathes usually about four 

 inches long, smooth, acu- 

 minate pointed. Racemes 

 at length long-exserted, two 

 to eight together, closely 

 approximate along the 

 shortened common rachis, 

 appearing digitate, more or 

 less spreading, densely flow- 

 ered ; joints about one-half 

 the length of the sessile 

 spikelet, usually with a den- 

 tate appendage at the im- 

 perfectly cup-shaped apex, 



Fia. 22. Andropogan provincialis Lam. Big Blue u a J J '1 



Stem -a, A sessile and pedicellate spikelet ; 6, fir^t Somewhat flattened and CU- 



glume of the sessile spikelet; c second glume of the Jatg along/ the edges the 



same; d, third glume; e, fourth or flowering glume . , . , ,, 



which is awned;/, palea; g, lodicuies. longer upper hairs one-halt 



