TETRAD YNAMIA SILIQUOSA. 1 47 



206. BRASSICA. 



1. B. Napus, root spindle-shaped ; leaves smooth, upper ones 

 lanceolate, heart-shaped at their base, clasping the stem, lower 

 ones lyrate, toothed ; flowers yellow. Rape-seed, 



Hat). Corn-fields and road-sides occasionally, but not any 

 where truly wild. May. $ 



64 Cultivated for the oil produced by the seeds ; and the 

 seeds, by pressure, are formed into cakes, which, after the 

 extraction of the oil, are useful for manure, as well as for 

 fattening cattle." 



2. B. Rapa, root stem-like, fleshy, orbicular, depressed ; radi- 

 cal leaves lyrate, rough, those of the stem smooth, the upper- 

 most entire ; flowers yellow. Common Turnip. 



Hab. Cultivated fields and their borders, but not wild. 

 April. $ 



As an object of agriculture, the Turnip was introduced into 

 this country by Lord TOWNSEND, in the reign 0f GEO. 1. 



207. SINAPIS. 



1. S. arvensis, rough; leaves toothed, partly lyrate or hastate; 

 flowers yellow ; pods with many angles, rugged, longer than 

 their own awl-shaped beak. Wild Mustard. 



Hab. Corn-fields, too common. May. Q 



2. S. alba, rough ; leaves lyrate ; flowers yellow ; pods bristly, 

 rugged, spreading, shorter than their own flat two-edged beak. 

 White Mustard. 



Hab. Corn-fields, common. June. Q 



Cultivated for the sake of the young herbs, which are used 

 in sallads ; and for the seeds, which have long been a po- 



Eular remedy in rheumatism, and of late have become 

 ishionable in dyspeptic complaints. 



3. S. nigra, lower leaves lyrate, upper linear-lanceolate, en- 

 tice, smooth, more or less pendulous ; flowers yellow, small ; 

 pods quadrangular, smooth, slightly beaked, close-pressed to the 

 stalk. Common Mustard. 



Hab. Fields and waste grounds. "North side of the 



G2 



