22 On the different Species, $c. of the Genus Brassica. 



loped at their basis in the shape of a heart, oblong, and entire 

 at the edges ; the flowers are constantly yellow, the leaves of 

 the calyx are half expanded, the seed-pods are upright, round, 

 perfectly tetragonal, swollen in a slight degree, and termi- 

 nated in a point, which is nearly quadrangular at its base ; 

 the seeds are brown, abundant, and tolerably large. This 

 plant is cultivated for the oil contained in its seed, and ap- 

 pears to be the most productive of any that are used for the 

 same purpose. But such is the confusion existing in the 

 nomenclature of these plants, that it is difficult to know, 

 without the minutest description, which are to be referred 

 to the same species. The one now under consideration 

 appears to be the true Colsa, cultivated in Belgium, and in 

 several of the eastern parts of France, in Germany, and 

 in Switzerland : in other provinces the name of Colsa is 

 given to the Brassica Napus oleifera, or Navette d hirer, 

 while the Brassica campestris oleifera is simply called 

 Navette. So we must refer the Colsa of Duchesne, and 

 Lamarck, to the Brassica Napus, as well as the plant de- 

 scribed in the Flora Britannica* under the name of Coleseed : 

 on the other hand, in the greatest part of the Netherlands, 

 and France, Colsa implies the Brassica campestris oleifera, 

 so that to prevent any mistake, I have chosen oleifera for the 

 methodical nomenclature, which is at least as comprehensible 

 as the names of Colsa and Coleseed, both merely signifying 

 Cabbage seed, in the German origin. It would be desirable 

 for agriculture that in all countries, cultivators would ex- 

 amine whether the plant they rear is the Brassica campestris 



* See Brassica Napus in Smith's Flora Britannica, Vol. ii. page 719: and 

 English Botany, plate 2 146. 



