183 



and the smiling aspect of the cultured country 

 beneath ; we beheld the plants divided by zones > 

 as the temperature of the atmosphere diminished 

 with the height of the site. Below the Piton, 

 lichens begin to cover the scorious lava with lus- 

 tered surface ; a violet *, akin to the viola de- 

 cumbens, rises on the slope of the volcano at 

 1740 toises of height; it takes the lead not only 

 of the other herbaceous plants, but even of the 

 gramina, which, in the Alps and on the ridge of 

 the Cordilleras, form close neighbourhood with 

 the plants of the family of eryptogamia. Tufts 

 of retama, loaded with flowers, make gay the val- 

 lies hollowed out by the torrents, and which are 

 encumbered with the effects of the lateral erup- 

 tions ; below the spartium, or retama, lies the 

 region of ferns, bordered by the tract of the arbo- 

 rescent heaths. Forests of laurel, rhamnus, and 

 arbutus, divide the ericas from the rising grounds 

 planted with vines and fruit trees. A rich car- 

 pet of verdure extends from the plain of spar- 

 tium, and the zone of the alpine plants even to 

 the group of the date trees and the musa, at the 

 feet of which the ocean appears to roll. I here 

 pass slightly over the principal features of this 

 botanical chart, as I shall enter hereafter into 

 some farther details respecting the geography of 

 the plants of the Isle of Teneriffe. 



* Viola cheiranthifolia. See our equinoctial plants, vol. i, 

 p 111, PL 32. 



