118 



now described for the first time. One, a large bush with pink 

 flowers, occurred in the Barranco de las Angustias on the western 

 side of the island, and has been named Echium Bond'Spraguei 

 (pi. fig. 3) in compliment to Dr. Thomas Bond Sprague, thanks to 

 \7h0m the writers were enabled to visit the Canaries ; the other, 

 which had white flowers and very short style-arms, was found in 

 the Barranco del Carmen on the eastern side of the island, and 

 has been named E. brevirame (pi. fig. 4). 



The five 'species, (1) giganteum^ (2) leucophaeum, (3) Bond- 

 Spragueiy (4) hremraine and (5) aculeatum^ constitute a very 

 natural group. To a certain extent they form a series in the 

 aboVe order, the two extremes of which are represented by 

 ffiganteuTn, which has the broadest and least spinulose leaves and 

 the longest style-arms, and aculeatum^ which has the narrowest 

 and most spiny leaves, and ftogether with brevirame) the shortest 

 style-arms. If the same series were traceable in the other charac- 

 ters and in the geographical distribution, there would be a prima 

 facie case for the union of the five species. A glance at the 

 accompanying plate and text-figure will show that these 

 conditions are not fulfilled. The corolla is more distinctly 

 zygomorphic in species (1) and (4) than in the others; and the 

 broadest and shortest calyx-segments occur in (2). Secondly, 

 the two extremes, (1) and (5), occur in the middle of the area of 

 distribution and the intermediates to the extreme east and west. 

 The most striking point in the distribution is that (6), though 

 restricted in Tenerife to a small area in the north-west, occurs 

 also in Gomera. It is the only species of the giganteum group 

 which is represented in two of the islands. 



2^N 



LA PALMA 



2aN 



GOMERA 





TLNERIFE 



18 w 



17 



16 W 



The following key should be used in conjunction with the plate 

 and the descriptions given in the enumeration, as it necessarily 

 contains only a selection of the distinctive characters : — 



Leaves narrowly oblanceolate, up to 3'5 cm. 

 broad, almost destitute ot spinules; 

 calyx-segments broadly linear; style- 



arms 2-2'5 mm. long (fig. 1) 



• • « 



* « 



1. E, giganteum. 



