CRUCIFEROUS TRIBE. 



61 



BARBAR^A vuLGARis (Common Winter Cress). 



18. NASTURTIUM (Cress). 



* Flowers white. 



1. N. officindle (Common Water Cress). Leaves pin- 

 nate ; leaflets roundish or oblong, toothed. Abundant 

 in rivulets and ponds, and, near large towns, extensively 

 cultivated as a salad. The only plant for which it can 

 well be mistaken by water-cress gatherers has hollow 

 leaf-stalks, and serrated leaflets, which this has not. 

 Fl. June August. Perennial 



* * Flowers yellow. 



2. N. sylvestre (Creeping Yellow Cress). Leaves pin- 

 nate; root creeping. Watery places; not common. 

 FL June September. PerenniaL 



