SPECIES AND VARIETIES. 197 



The cultivated forms of this species include the garden Cab- 

 bage, Cauliflower, Kale, etc. 



ff Upper leaves stem-clasping with auricles. 



B. campestris : annual ; stem 12 feet high, erect, simple, 

 or scarcely branched; leaves green, slightly glaucous, pinnately 

 divided, with a large terminal lobe, rough with stiff hairs, which 

 are rarely wanting, upper ones narrow-oblong or lanceolate, 

 stem-clasping, with rounded projecting auricles ; flowers bright 

 yellow; pods resembling those of the last. Borders of fields and 

 waste places, a frequent weed of cultivation. Fl. June, July. 



The cultivated varieties include the Turnip (B. Napus), the 

 Rape-seed or Colza (B. Rapa), etc. 



(28) Sinapis. MUSTARD. 



* Pods spreading from the axis of the inflorescence. 



S. alba : annual; stem 1-2 feet high, glabrous or with spread- 

 ing hairs ; leaves lyrate, i.e. pinnately lobed or divided, the ter- 

 minal one largest, the lobes ovate or oblong, coarsely toothed ; 

 flowers rather large, yellow; pods spreading, knotty, hispid 

 with stiff hairs, shorter than the sword-shaped beak. Waste 

 and cultivated places; often cultivated for salad. Fl. June. 



S. arvensis : annual ; stem 1-2 feet high, with a few spread- 

 ing hairs ; leaves rough, the lower ones with one large terminal 

 oval-oblong, coarsely-toothed segment, and a few smaller ones, 

 the upper often undivided ; flowers yellow, rather large ; pods 

 spreading, about a third occupied by a stout awl-shaped beak, 

 the valves glabrous, or rough with reflexed hairs. Charlock. 

 A common weed of cultivation. Fl. June, July. 



** Pods erect, oppressed to the axis of inflorescence. 



S. nigra : annual, less hairy than the preceding ; stem two 

 feet high ; leaves deeply divided, with one large terminal ovate 



