PLANT LIFE OF THE CANARY ISLANDS. 76 j 



dock often seen on the steeper hillsides, and occasionally a shrubby 

 Convolvulus. The Echiums reach great development on the islands. 

 There are several peculiar species. The immense spikes of white or 

 blue flowers are a common and striking feature of the landscape. 

 Shrubby Hypericums also abound, both on hillsides and in barrancos. 



The so-called " barrancos " are a rich field for the collector. 

 They are deep, narrow cracks between hills which have been sun- 

 dered by volcanic disturbance. Erosion has had little or no part in 

 their formation. Many of them are not watered at all, and if fol- 

 lowed to their sources are foimd to end blindly among the hills. In 

 some the winter rains collect and remain as stagnant pools or slow- 

 flowing streams through a part or the whole of the year. Others are 

 beds of perennial brooks fed by springs among the hills, and some- 

 times, in seasons of heavy rains, the waters rise above their narrow 

 channels and rush in floods to the sea, causing great devastation 

 among the fields and homes of the farmers. Teneriffe, Canary,, 

 Palma, and Gomera are supplied with such streams and springs. The 

 whole island of Lanzarote has only two insignificant and inaccessible 

 springs; Fuerteventura is slightly better off, while Hierro is entirely 

 dependent upon rain water, which is carefully stored in cisterns. 



Valleys, of which there are notable ones — such as that of Ora- 

 tava, called by Humboldt the finest in the world — are distinguished 

 from barrancos by greater breadth and less precipitous sides, and are 

 not necessarily volcanic in their origin. 



The exploration of a barranco is a fruitful occupation. Rare 

 orchids and many ferns spring from between the damp rocks. A 

 shrubby crucifer is occasionally seen on precipitous ledges, and more 

 commonly an equally curious spiny and woolly-leaved composite. 

 The blackberry, which is common in all sorts of localities, here takes 

 on peculiar forms, and leafless suckers thirty feet long swing down 

 the bare cliffs, seeking rooting place. 



The bottoms of the watered barrancos and valleys are scenes of 

 tropical luxuriance. The carpet of vivid grass is studded with loose- 

 strife, oxalis, and clover. Wild forget-me-nots love the turf closest 

 to the springs, and our garden nasturtium flings bright-flowered 

 trailers profusely over the banks of the brooks. ]\raidenhair fronds 

 grow in delicate beauty under the dripping ledges of the rocks. The 

 tiny-flowered speedwell carpets retired nooks, and a species of Lathy- 

 rus with large, royal purple blossoms tangles itself around the canes. 

 Here and there are clumps of palm and of native willow, rarely a 

 specimen of the once common Dracaena draco, the famous dragon 

 tree which yields the red gum once so esteemed as a dye and used by 

 the aborigines in embalming their mummies. This tree is by some 

 thought to symbolize the dragon which guarded the golden apples 



