446 THE SMALL GRAINS 



instance is known to the author in which winter barley 

 was almost all winter killed, and was replaced the follow- 

 ing summer with a good and fairly uniform stand of chess. 

 Because of this quick replacement of the crop by chess, 

 often observed by farmers, they naturally conceive the 

 idea that wheat changes into chess. Chess is rare in 

 spring grain, unless the latter is grown on fall plowing. 



The panicles of chess are loose with drooping branches, 

 and have many-flowered hairless spikelets. 



The florets of chess are swollen a little above the 

 middle, the lemma rounded on the back, obscurely 7- 

 nerved and awned. The palea bears a single row of stiff 

 hairs (Fig. 142 a). Chess is one of the brome-grasses, of 

 which several are common weeds in different parts of the 

 country. The seeds are objectionable in wheat for mill- 

 ing, as they give the flour a dark color and a disagreeable 

 flavor. Two other brome-grasses (B. steriles and B. 

 tectorum) are sometimes equally as bad weeds as chess. 



Seeds of chess separate from wheat with some diffi- 

 culty. The seeds should never be allowed to mature. 

 A rotation including an intertilled crop, with thorough 

 cultivation and use of clean seed, will keep out the weed. 

 Chess makes fair hay, and therefore should by all means 

 be cut green for hay, rather than be allowed to ripen seed. 



485. Common ragweed (Ambrosiaartemisicefolia,'Lmi\.) 

 is a bad weed in grain fields nearly everywhere, but only 

 because of the green plant in the sheaves. The seeds do 

 not often go into the grain, and even then are readily 

 separated. The species here mentioned is frequent in 

 the eastern states and southwest Ontario. In the Great 

 Plains another species prevails (507). 



Common ragweed is a coarse branching plant, with 

 heavy stems, 2 to 4 feet high, leaves thin, twice pinnatifid, 



