INSULAR FLORAS. 389 



Vinos was 9*5 metres in circumference at 2*5 metres from 

 the ground in 1857 ; and this had increased to 117 metres 

 in 1884. Shrubby and half-shrubby Composite, and 

 numerous species of the boragineous genus Echium abound ; 

 but the fleshy-leaved Crassulacea; give character to the 

 vegetation. The latter mostly belong to the type having 

 the leaves arranged in dense, often large, rosettes, from 

 which rise the leafless inflorescences. Nowhere else in the 

 world is there such a concentration of this class of plants ; 

 no fewer than fifty-two species being enumerated by Christ, 

 mostly belonging to the genus Sempervivum. S. tabulceforme 

 forms rosettes as much as fifteen inches across ; and, con- 

 trary to what is generally supposed, the roots of these 

 succulent plants penetrate the fissures of the rocks to an 

 incredible depth in search of moisture. Statice is another 

 prominent genus of perennial duration, being represented by 

 about a score of species. Apart from weeds of cultivation, 

 there is very little truly herbaceous vegetation, and bulbous 

 plants are rare. 



The " cloud region ' : is a zone above cultivation, which 

 is almost constantly enveloped in clouds, engendering a 

 green or leafy vegetation. It is the zone of the laurel 

 forest, consisting of Persea indica, Lauras canariensis, 

 Oreodaphne fastens, and the much rarer Phoebe barbusana. 

 With the exception of the last, which only extends to 

 Madeira, Dr. Christ records these laurels as common to the 

 Canaries, Madeira, and the Azores ; but this is probably 

 a slip so far as the Oreodaphne is concerned. They are, 

 however, all confined to the Atlantic Islands. Erica arborea, 

 Myrica Faya and Pteris aquilina are the three predominat- 

 ing species in the undergrowth ; the two first being both 

 arboreous in the forest itself. Endemic species of Ilex, 

 Myrsine, Notelcea, Clethra, Arbutus, and Visnea, are other 

 noteworthy elements of the vegetation of this zone. 



Teneriffe alone has a subalpine region above the forest, 

 with a dry, scorching climate and a thinly-scattered vegeta- 

 tion, consisting largely of Spartium supranubium. Her- 

 baceous plants are sparse and of a greyish hue, such as 

 Viola cJieirantJiifolia and Silene uocteolens. 



Taking Sauer's estimate of 1226 (31), as representing 



