INSULAR FLORAS. 393 



plants ; one-third of which he regards as introduced plants. 

 Of the remaining 121 indigenous species many are endemic; 

 but Tornabenia (Umbelliferai) is the only endemic genus ; 

 indeed, the only one peculiar to the Archipelago. On the 

 hillsides, from an altitude of about 1 300 feet to the summit, 

 the shrubby Euphorbia Tztckeyana forms thickets, in some 

 places as much as eight feet high, but usually not more than 

 three. Prominent among the endemic plants associated 

 with the Euphorbia are : Echium stenosiphon, Sarcostemma 

 Daltoni, Sempervivum Webbii and Lavandula rotundifolia. 

 Altogether, about two-thirds of the species inhabiting the 

 uplands are endemic. 



With regard to the affinities and origin of the flora of 

 the Cape Verd Islands, Krause in the main agrees with 

 Christ ; but he carefully distinguishes between the two 

 questions. He finds the nearest affinity in the southern 

 half of the Canaries, relying largely on the Euphorbia and 

 Dracczna elements. Draccena Draco has disappeared from 

 the island of St. Vincent ; but is still said to exist here and 

 there in the mountains of St. Nicolao and St. Antonio. 

 But the total absence of the Genistece, Laurinece, Chrysan- 

 themum, Rhodorhisa, and Phcenix, and the comparative 

 rarity of other characteristic Canary plants, points rather to 

 community of origin than to community of descent. Neither 

 Christ nor Krause will admit of a former land connection of 

 the four groups of Atlantic islands ; and the latter regards a 

 former connection of the Cape Verd Islands with the con- 

 tinent as highly improbable. Yet, as before stated, Dr. 

 Christ regards the floras of the islands from the Azores to 

 the Cape Verd as more nearly related to each other than 

 separately to any part of the continental flora. Neverthe- 

 less, I agree with H. C. Watson (39) that the flora of 

 the Azores corresponds closely to that of South-western 

 Europe. His list of plants, which occur in the Azores, 

 but not in Europe, and are also common to Madeira or the 

 Canaries, or both, is a very small one, and, as he himself 

 suggests, might be considerably reduced, as it includes a 

 number of plants of wide distribution, among them some 

 that are only colonists in any of the Atlantic islands. 



