98 FARM WEEDS OF CANADA 



GREEN TANSY MUSTARD (Sisymbrium incisum Engelm., var. 



filipes Gray) 



Other English name : Cut-leaved Tansy Mustard. 

 Other Latin name: Sophia incisa (Engelm.) Greene. 



Native. Biennial; in the first season, a rosette of finely 

 divided leaves lying on the ground. Stems, 3 to 4 feet, erect, 

 widely branching at the top and bearing an enormous number 

 of narrow, smooth, slightly curved pods, from 1/2 to 3/4 inch long, 

 on slender, spreading footstalks. Whole plant bright green 

 and somewhat glandular. Leaves pinnatifid, each division 

 sub-divided into 2 or 3 linear-oblong segments, with or without 

 teeth. Flowers yellow, 1/8 inch across in an elongated raceme. 



The seed (Plate 73, fig. 40) is small, 1/25 of an inch long, 

 oblong, sometimes compressed at the scar end, reddish brown, 

 minutely roughened with mucilaginous hairs. 



Time of flowering: July; seeds ripe in August. 



Propagation: By seeds. 



Occurrence: In grain crops in the Prairie Provinces and 

 British Columbia. A wayside weed in eastern Canada, where 

 it is common along railways and where western grain or mill 

 feeds have been distributed. 



Injury: A weed of rank growth and branching habits that 

 crowds out grain, greatly reducing the yield. Its bulky nature 

 makes the operation of harvesting machinery difficult and extra 

 binder twine necessary. 



Remedy: The prevalence of this biennial mustard in grain 

 fields of the Prairie Provinces is largely due to the practice of 

 sowing cereal grains on stubble land, with only surface cultivation 

 in the fall or spring to produce a suitable tilth for a seed-bed, 

 without first destroying weed growth by plowing, thorough disc- 

 ing or the use of a broad-shared cultivator. Summer-fallows 



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