﻿Vol. 25 



No 7. ' 



BULLETIN 



OF THE 



TORREY BOTANICAL CLUB 



JULY 1898 



A Sketch of the Flora of the Canary Islands. 



By Alice Carter Cook. 



The Canary Islands have the latitude of central Florida and 

 are at the nearest point but seventy miles distant from the coast of 

 the Sahara. Three islands lie to the east and three to the west of 

 Tenerife, the largest member of the group, famous for its magnifi- 

 cent snow-capped volcano over 12,000 feet high. The geologic 

 formation is entirely volcanic and the evidences of former seismic 

 activity are everywhere apparent in the exceedingly mountainous, 

 broken and jagged nature of the land surface. 



The climate is semitropical and the average winter and sum- 

 mer temperatures differ only by about io° C. There are clearly 

 marked rainy and dry seasons — the former usually beginning in 

 October and lasting until March. Whether the islands were once 

 connected with the mainland or not is still a disputed question. 

 The Challenger Report describes them as joined to Morocco and 

 to Portugal by narrow submarine elevations. The flora has much 

 >n common with the Madeira and Cape Verde groups, but its gen- 

 eral character is that of the Mediterranean region, including North 

 Vf nca. A number of plants (species of Erica, Umbilicus, Wahlcn- 

 bc '-gia, Romulca, etc.) have South African affinities ; others (species 

 of Visnea, Phoebe, Bosea, Myrica, etc.) Indian, and still other 

 (species of Ptcris, Asplenium, Pin us, Salix, etc.) American. But 

 the l ar g e proportional number (414 out of 1,226) of species* 

 Peculiar to the islands proves long isolation. Knowledge of the 



<lls tnbution of Canary plants and comparative study of them and 



Christ in Engler's Bot. Jahrb. 6 -. 459-526. 1885 



[Iwwd 15 July 1898.] (351) 



