10 Geographical Distribution of the Crucifera. 



Oregon Territory, such as the L. integrifolium and L. montanum. 

 The Lepidium Menziesii, first known on the north-west coast, 

 was also gathered by Drummond in the Rocky Mountains, after- 

 wards by Nuttall on the same ranges farther south. We can 

 merely name the Californian species, the L. oxycarpum and 

 L. latipes, discovered by Douglas ; the L. Calif or niciun, lasiocar- 

 pum, and nitidum, by Nuttall. 



The Capsella bursa-pastoris, or Shepherd's Purse of the 

 old countryman, is well diffused over the whole country to the 

 roots of the Rocky Mountains westward, and to Great Bear's Lake 

 northwards. About this, our well-known old friend, there is never 

 any mistake. The declared plague of the pasture, and detested 

 by the industrious gardener, the bursa-pastoris nevertheless 

 gladdens our eye with its homely and home-like look, reminding 

 us of early days and all their associations, the country road, the 

 cotter's kale-yard, and other long-forgotten scenes. 



The third division of our order, the JVucamentosce, contain- 

 ing the ninth tribe, the Isatidece of Decandolle, furnishes us 

 with but one genus on this continent, the I. thysahocarpus of 

 Hooker, of which all the species lie west of the Rocky Mountains. 

 The /. curvipes, upon which the genus was founded, was dis- 

 covered by Douglas at the Great Falls of the Columbia ; and the 

 /. oblongefolius was first discovered by Nuttall as being native 

 of the same country, but much lower down the river, at the junc- 

 tion of the Willamet. Four others are Californian, the /. elegans 

 and pulchellus of Fischer and Meyer, and the /. crenatus and laci- 

 niatus of Nuttall. 



In the fourth division Lomentacece is the tenth tribe, Cahi- 

 inece, in which w r e have the genus Cakile. The single species, 

 C. Americana, is a strange-looking plant, known in English as 

 the Sea Rocket. The pods are constricted, and have trans- 

 verse separations, forming one celled, one seeded joints. It 

 is not apparently a common plant, but occurs near the sea, and 

 on the shores of the oreat lakes of Canada. I have seen it on sand 

 along the north bank of the great St. Lawrence River, from the 

 Gulf up as far as the Saguenay. Its fleshy leaves no doubt enable 

 the Cakile, although on a smaller scale than the purely succulent 

 orders, such as the Cacti, &c, to assimilate much of its sustenance 

 from the air; nature thus, by wise modifications of structure, 

 compensating liberally in one way, for what may be wanting or 

 &tinted in another. I have been sometimes surprised at the fresh- 



