GRASSES OF IOWA. 



63 



9. PANICUM COGNATUM. 



Panictim cognatum Schultes Mant. 2: 235. 1824. Scribner. Bull. U. 

 S. Dept. Agr. Div. Agros. 17: 51. f.347. 1S99. 



Panicum autumnal e Bosc. Spreng. Syst. 1: 320. 1825. Watson and 

 Coulter. Gray. Man. Bot. 630. 1890. Scribner. Grasses of Tenn. Bull. 

 Univ. Tenn. Agr. Exp. Sta. 7: 44. 1894. Beal. Grasses of N. A. 2: 122. 

 1895. Vasey Contr. U. S. Nat. Herb. 3: 33. Nash in Britton and Brown, 

 111. Fl. 1: 124. f. 34. 1896. 

 Panicum divergent Muhl. Gram. 170. 1817. 



description. 

 Diffuse Purple Pani- 

 cum. Perennial with erect 

 or decumbent culms, i to 2 

 feet (2|-5 cm.) high, gener- 

 ally much branched at base, 

 slender. Sheaths shorter than 

 the internodes, the upper glab- 

 rous, the lower sometimes 

 densely pubescent ; leaves \\ 

 to 4 inches (3-8 cm.) long, 1 

 to 3 lines (2-6 mm.) wide, 

 ascending, acuminate, glab- 

 rous; panicle 5 to 12 inches 

 { 10-24 cm.) long, bearded in 

 the axils, the lower branches 

 4 to 8 inches (9-16 cm.) Long, 

 at first erect with the lower 

 portions included in the up- 

 per sheath, finally exserted 

 and widely spreading at ma- 

 turity; spikelets lanceolate, 

 about 1 \ lines (3 mm.) long, 

 acuminate, glabrous or pubes- 

 cent, on capillary pedicels, of 

 many times their length ; first 

 scale minute; second and 

 third, equal. Acute, glabrous 

 or sometimes villous, the 

 fourth lanceolate, 1] line (2O 

 mm.) long. 



Panicum cognatum. — a, /<, c, spikplets; 

 flowering glumes. (Div. Agros. U. 8. Dept. 



d. c, 



Agrl.) 



Panicum cognatum has been found in eastern Iowa only on sandy 

 beaches of the Mississippi, Iowa and Cedar rivers. It is abundant on 



