CHAPTER 111. 



OP THE WEEDS WHICH ARE PRINCIPALLY OBJECTIONABLE AS 

 THEY ENCUMBER THE SOIL, OR WHOSE ROOTS ARE ANNUAL, 

 AND WHOSE SEEDS PASS THE CORN SIEVE. 



Of this class of weeds, the following deserve particular 

 notice: — 1. Charlock; 2. Corn-poppy; 3. Blue-bottle 5 

 4. Mayweed, or Mather ; 5. Corn-marigold. 



1. CHARLOCK. 



This weed was before alluded to, when speaking of those 

 weeds which infest samples of corn ; but as the seed is suffi- 

 ciently small to pass through the corn-sieve, its presence in 

 samples must be owing to careless winnowing. There arc 

 four different species of plants confounded under the name 

 of charlock, viz. sinrqyis arveiisis, or common wild-mustard ; 

 sinapis nigra, black or Durham mustard ; raphanus rapha- 

 iiistrwn, wild radish ; bi'assica napus, wild navew : this last 

 is the least common. 



Sinapis arvensis has pods with many angles, swoln, and 

 bulged out by the seeds, smooth, longer than the two- 

 edged beak. It is also called Chadlock, Wild Mustard, 

 Corn-cale. Blossom yellow, and without veins. Root 

 annual ; flowering in May. 

 Sinapis nigra. Pods rough, laid flat on the spike stalk. 

 Blossom pale yellow ; pods slightly hairy. Root annual ; 

 flowering in June. 

 Raphanus raphanistrum. Calyx upright, close ; pods round, 

 jointed, smooth, of one or two cells. Blossom varying 

 in colour from yellow to straw and white, striped with 

 purple veins. Root annual; flowering in June and 

 July. 



