SEEDS — WEEDS. 



653 



The Russian thistle, C. S. Grand all {Colorado 8ta. Bui. 28, pp. 12, 

 figs. 8). — A poi)ul:ir and scientific bulletin describing the Eussian 

 thistle {Salsola l-ali tragus). This weed has been reported in 17 coun- 

 ties in Colorado, and attention is called to it in order that its spread 

 may be hindered as much as possible. In addition to the Kussian 

 thistle 2 other common tumbleweeds are figured that they may not be 

 confused Avitb it, viz, the common tumbleweed {Amaranthus alhns) and 

 the winged pigweed (CyelolomaplatyphyUum). 



The Russian thistle, H. Snydek {Minnesota Sta. Bill. 34, pp. 

 34-36). — The author has made a study of the Russian thistle to deter- 

 mine its food value and draft ui^on the soil. When young the thistle 

 is claimed to have a high food value, especially for sheep, which, some 

 claim, are attracted to it merely on account of the salt which it con- 

 tains. The chemical analysis shows a large percentage of ash mate- 

 rial, amounting to nearly one fifth of the dry weight of the plant. 

 This is a serious objection to its use as a fodder, on account of the alka- 

 line nature of the mineral matter present. One favorable i^oint, as 

 shown by the analysis, is the large amount of nitrogenous matter 

 present, being as much as there is in clover or rape. Of the nitrogen 

 present from Qb to 80 per cent is available in the form of protein. 

 Before the development of the thorns there is not much fiber present, 

 at this time the jilant is more valuable as a food than when mature. 

 When the plant is ripe the fiber and mineral matter make up half of 

 its composition, and although rich in nitrogenous matter the former 

 elements greatly reduce its feeding value. The following table shows 

 analyses of plants of different ages: 



Compoiiition of the liusslan thistle. 



COMPOSITION OF THE DIIY MATTEli. 



The ash analysis shows that the weed has strong fjraging powers, 

 there being large amounts of i)otash and lime taken up by the plant. 

 The draft which the plant makes upon the sodium in the soil is a bene- 

 fit to alkali lands. The amount of sodium present varies greatly with 



