MARITIME PLANTS. 25 



the shores of our own country ; and in similar 

 spots the handsome purple sea-lavender is to b& 

 seen in abundance. On the coasts of the- 

 Mediterranean, two fleshy-leaved plants, with 

 inconspicuous flowers, (Salsola kali, and Sal- 

 sola soda,) are found in great abundance, and 

 are burned in large quantities for the sake of 

 their ashes, which contain much soda. These, 

 when packed in barrels, are imported into this 

 country under the name of Barilla, which was 

 formerly used extensively in various manufac*- 

 tures, especially that of soap, and is still to 

 some extent, though mostly superseded by the 

 use of soda manufactured from common salt. 



On the sea-coasts of tropical climates, where 

 the shores consist of mould, partly firm and 

 partly marshy, and which are accessible to the 

 tide, and often covered by it, vast forests occur, 

 which frequently extend for miles along the coast. 

 In the West Indies, South America, and the 

 west coast of Africa, these consist of the man- 

 grove, (Rhizophora mangle.) This is a very 

 curious tree, seldom exceeding forty or fifty feet 

 in height, and is green through the year.. 

 Unlike most other trees, its roots are not all 

 under ground, but the lower portion of the 

 stem divides into roots at a considerable height 

 above the soil, and these again subdivide, so as 

 to form a complete vault of roots, from the 

 summit of which the trunk springs. The tree 

 is thus mor,e firmly and extensively fixed in the 

 loose, swampy ground, in which it flourishes. It 

 differs from other plants also in another remark. 

 3 



