Manchester Memoirs, Vol. ixii. (iQi8), No., . 



VIII. Regional Distribution of the Native Fl 

 Teneriffe. 



By J. H. Salter, D.Sc. 



[Communicated by Professor F. E. Weiss, D.Sc, F.L.S., F.R.S.) 



(Read November 13th, 19 17. Received for publication March 5th, 19 18.) 



The island of Teneriffe, lying in latitude 28 N., longitude 

 16 W., is the largest of the Canarian group, having an area of 919 

 sq. m. (2352 sq. kils.). Occupying a median position in the, Canarian 

 archipelago, the flora of Teneriffe has less of a Saharan character 

 than that of the eastern islands which lie much nearer to the African 

 continent, while not quite so markedly Atlantic in character as that 

 of the western islands (La Palma, Gomera and Hierro) which lie 

 outside it. It results from the shape of the island that it has three 

 stretches of coast : (1) facing N. to N.W., (2) an equally long stretch 

 facing S.E., and (3) a shorter stretch facing S.W., but for the sake of 

 simplicity No. 1 may be termed the north coast, Nos. 2 and 3 together 

 the south coast. The salient structural feature of the island is the 

 central ridge ("Cumbre"), which, originating near the Lighthouse, 

 attains to about 950 m. in the Cumbre de Anaga, but is interrupted 

 at the point where La Laguna, situated upon a broad saddle at a 

 height of only 550 m., stands in the midst of a green oasis, the only 

 wide, continuous and level stretch of cultivation in the island. 

 Rising again at Esperanza, and now fringed with pines, the cumbre 

 runs in a south-westerly direction as a" divide " of gradually 

 increasing height, and at Pedro Gil, the pass by which Orotava 

 communicates with Guimar, is already some 2030 m. above sea-level. 

 Continuing its course at a still higher elevation (2300 m.), it presently 

 divides to form the encircling edge of a great saucer-shaped depres- 

 sion (some 13 kils. across), in the centre of which rises the cone of the 

 Peak, the culminating point of the island. This depression, sur- 

 rounding the base of the Peak, lying at a height of about 2135 m. 

 (7000 ft.) and encircled upon its outer side by arid cliffs of basalt 

 and trachyte, which in places rise a couple of thousand feet higher, 

 forms the curious region known as the Cafiadas. It follows from the 

 position of the Peak that the downward slope, from the edge of the 

 Cafiadas to the sea, is much wider and less abrupt upon its southern 

 than upon its northern side. This southern region, the Bandas del 

 Sur, is a hot and arid district, much of it semi-desert. The flanks 

 of the central ridge are everywhere furrowed by a series of rocky 

 ravines (known as " barrancos "), extending to the sea and having 

 apparently been formed by the action of streams. At the present 

 day they are perfectly dry, at any rate in the coastal region, except 

 at intervals of several years, when, as the result of an exceptional 



