446 



WB^D FLORA OF IOWA 



arvensis; taste pungent. Generally found in seed of clover and 

 alfalfa. 



Indian Mustard {Brassica juncea). 



Seed about the size of wild mustard seed ; surface rather coarsely 

 reticulated. Color dark reddish brown. 



^e^^A^^i^^^^-^&j^M. 



^^s^sG-sija^Si^'^ '/v,^ 



e 3 



-1 



c 



^0-. 



Figure 296A Figure 296B 



Fig. 296. A. Indian Mustard (.Brassica junoea). B. Hare's-ear Mustard 

 (Conringia orientalis). a, b, different views of seed; c, cross section; d, 

 natural size. 



(After Hillman, Bull. Mich. Agr. Exp. Sta.) 



Hare 's-ear Mustard {Conringiat orientalis (L.) Dumort.). 



Pod rigid, 4-angled; seeds brown, oblong narrowed to rounding 

 at the ends, 2-2.5 mm. long; surface finely reticulated in checks; 

 sear at end of seed lighter in color; position of caulicle indicated 

 by two distinct, lengthwise grooves. 



Tumbling Mustard {Sisymbrium altissimum L.). 



Seed oblong flattened, one-twenty-fifth in. in length ; color reddish 

 yellow; radicle prominent, variable in shape; form of embryo 

 marked by deeper color, by lines; seed coat becomes mucilaginous 

 when wet. A tumbling weed. Distribution wide, reported as a 

 serious weed in commercial seeds of the northwest and Canada. 



Hedge Mustard {Sisymbrium officinale (L.) Scop.). 



Seed oblong, sometimes with upper end truncate, some almost 

 trapezoidal in outline, one-twenty-fourth to one-sixteenth in. long; 

 color yellowish, or brownish, variable ; caulicle evident from promi- 

 nent white sear; funide sometimes present and pointed; seed coat 

 mucilaginous. Found in alsike and white clovers. 



