177 



25 -2° to 26-3°. The first plant that we gathered 

 on the continent of America was the avicennia 

 tomentosa*, which in this place scarcely reaches 

 two feet high. This shrub, the sesuvium, the 

 yellow gomphrena, and the cactus, cover the 

 lands impregnated with muriat of soda ; they 

 belong to that small number of plants, which 

 live in society like the heath of Europe, and 

 which in the torrid zone are found only on 

 the seashore, and on the elevated plains of the 

 Andes «f\ The avicennia of Cumana is distin- 

 guished by another peculiarity not less remark- 

 able : it furnishes an instance of a plant com- 

 mon to the shores of South America and the 

 coasts of Malabar. 



The Indian pilot led us across his garden, 

 which rather resembled a copse than a piece of 

 cultivated ground. He showed us, as a proof 

 of the fertility of this climate, a silk-cotton tree 

 (bombax heptaphyllum), the trunk of which, in 

 it's fourth year, had reached nearly two feet and 



the city 30 2° ; water of the Manzanares 25*2° : at four in 

 the afternoon, flow 25*3° ; air near the coasts 26 2°^ air at 

 Cumana 28*1° j water of the Manzanares 25'7°. 

 * Mangle prieto. 



+ On the extreme rarity of the social plants between the 

 tropics, see my Essay on the Geog. of Plants, p. 19 j and a 

 paper by Mr. Brown on the Proteacece (Trans, of the Lin. Soc. 

 vol. x, P. i, p. 23), in which this great botanist has extended 

 and confirmed by numerous facts my ideas on the associa- 

 tions of plants of the same species. 



