2 Salter, Flora of Teneriffe. 



fall of rain, they are for a few hours converted into^water-courses 

 once more. 



General Character of Vegetation 



The special interest of what Dr. Christ terms " diese wunder- 

 reichsten und liebreizendsten aller Floren " was recognised even 

 before the date of Humboldt's visit (1799), when he found the Botanic 

 Garden at Orotava already in existence. One is at once struck by 

 the " evergreen " character of the native vegetation and by the large 

 proportion of shrubby or arborescent forms. Amongst the latter, 

 representative of genera which in Britain are wholly or chiefly 

 herbaceous, are the following: — Senecio {Cineraria), five or six 

 species ; Sonchus, nine or ten species ; Convolvulus, five or six 

 species ; Echium, four or five species ; Plantago, one species ; Rumex, 

 one species, and Euphorbia, eight species. Add a large number of 

 shrubby Compositae not enumerated above and the numerous wood}', 

 branched species of Sempervivum. 



Endemic forms constitute an unusually large proportion of the 

 native flora. Taking Sauer's list as basis, we find 333 endemic 

 species enumerated out of a total of 1250 Canarian plants — i.e. 27 

 per cent. But if casuals, denizens and cosmopolitan weeds be ex- 

 cluded, and if, with the Canarian group, we include Madeira and the 

 Azores, the proportion rises to 50 per cent. Certain genera stand 

 out strikingly in this respect, the genus Sempervivum (as now divided 

 into Aichryson, Monium and Greenovia) presenting an extraordinary 

 case. This may be shown concisely as follows, the denominator of 

 the fraction indicating the number of Canarian species, and the 

 numerator showing how many of these are endemic : — Genista, §■ ; 

 Polycarpcea, |- ; Sempervivum, ^ ; Argyranthemum, $ ; Senecio (of 

 Cineraria section), ^ ; Sonchus (arborescent), yi J Convolvulus 

 (non-herbaceous), i 9 T ; Echium, -^ ; Bystropogon, -f ; Micromeria, 

 yt > Sideritis, f ; Statice, jf- ; and Euphorbia (non-herbaceous), §-. 

 It is instructive to compare in this respect two important Natural 

 Orders, both largely represented in the Canarian group : (1) Legu- 

 minosse with 120 species. The bulk of these are small vetches and 

 trefoils of wide distribution, so that of endemic forms we find only 

 three species of Dory cnium, two of Vicia (V . filicaulis and V. cirrhosa, 

 thread-like and all but leafless) and five of Lotus, of which only 

 three occur in Teneriffe. On the other hand, (2), the Compositae 

 are still more largely represented by about 170 species, of which no 

 less than 80 are endemic. 



The native flora of Teneriffe is fortunately in no danger of 

 extinction. Not more than one-seventh of the steep and rugged 

 surface of the island is capable of cultivation. In the barrancos, 

 upon the sea-cliffs, the old lava-flows and the rocky outcrops which 

 everywhere occur, the indigeneous flora in varied and characteristic 

 forms has it practically all its own way. 



As Hooker points out, the Canarian flora generally, and this 

 applies also to that of Teneriffe, contains many plants which are 

 more nearly allied to Mediterranean species than to those found 



