GRASSES OF IOWA. 57 



dianola (Carver); Des Moines (Wallace); Newton (Misses Cava- 

 nagh and Dilne) ; Hamilton to Hancock County (Preston); Mason 

 City ( Pammel ) . 



North America. From Nova Scotia to Ontario; New England 

 smith to Florida, New York (Perm Yan, Sartwelt, Washington 

 County, Parry); Missouri, Kansas, Nebraska, Iowa, Minnesota, Wis 

 consin, Michigan, Ohio (Columbus, Sullivant). 



General. British Islands, Germany, France and eastward, gen- 

 erally in temperate and tropical regions. 



6. PANICUM SANGUINALE. 



Panicum sangninale L. Sp. PI. 57. 1753. Watson and Coulter. Gray. 

 Man. Bot. 630. 1890. (6ed.). Scribner. Grasses of Tenn. Bull. Univ. Tenn. 

 Agr. Exp. Sta. 7: 38. /. 26. 1894. Bull. U. S. Dept. Agr. Div. Agros. 

 .17:43. /. 339. 1899. Scribner and Merrill. Rhodora 3: 99. Vasey. Contr. 

 U. S. Nat. Herb. 3: 25. Beal. Grasses of N. A. 2: 110. 1896. 



Svnfherisma sanguina/is (L.) Nash in Britton and Brown. Ill Fl. 1: 

 111. /. 240. 1896. Nash. Bull. Torr. Bot. Club. 22: 420. 1895. 



Syntherisma praecox Walt. Fl. Car. 76. 1788. 



Digitaria sa?iguinalis Scop. Fl. Carn. 1: 52. 1772. (2ed.) 



Paspalum sanguinale Lam. Tabl. Encycl. 1: 176. 1791. 



DESCRIPTION. 



Crab Grass or Finger Grass. A much-branched, leafy annual, 

 more or less decumbent at the base, and often rooting at the Lower 

 joints. Culms smooth, i to 3 or 4 feet (\ to 8 or 10 dm.) long, 

 ascending; nodes smooth or sometimes bearded with deflexed hairs. 

 Sheaths loose, smooth or pilose hairy, usually ciliate on the margins; 

 ligule membranaceous, about 1 line (2 mm.) long; leaf-blade flaccid, 2 

 to 5 inches (4-10 cm.) long, 2 to 4 lines (4-8 mm.) wide, Hat, acute, 

 scabrous, sometimes sparingly pilose, and with the sheaths sometimes 

 purple tinged. Racemes four to ten, digitate or subfasciculate at the 

 apex of the culm, -i to 5 inches (6-10 cm.) long, usually spreading. Spike- 

 lets about 1^ lines (3 mm.) loot:, lanceolate, acute, in pairs, one nearly 

 sessile, the other distinctly pedicellate; first glume very minute, the sec- 

 ond one-half to two-thirds as long as the spikelet, usually ciliate on the 

 margins and three-nerved; the third a little longer than the fourth, five- 

 nerved, and usually silky-villous along the marginal nerves; fourth 

 glume smooth, very acute. A weed in cultivated fields and lawns. June 

 to September. 



Crab grass is widely naturalized. It now occurs in all parts oi 

 the state. It is a troublesome weed in cultivated fields. 



