Notes on the Summer-Fall of the Leaf 

 on the Canary-Islands. 



By 



M. Va hi. 



Wh ile under a short stay on the Canary-Islands, Tenerife and 

 Gran Canaria in the summer of 1902 I got an opportunity of 

 observing a certain peculiarity about the vegetation of the low- 

 country, which I had not seen mentioned in literature, namely the 

 frequent occurrence of summer-fall of the leaf. 



The vegetation in the arid low-country is made up of highly 

 xerophile shrubs, which stand, however, so widely scattered that 

 the stony soil is everywhere visible and imparts its colour to the 

 landscape. Among the common shrubs only Euphorbia canariensis 

 and Kleinia neriifolia reach to above a man's height; the other 

 shrubs are small or dwarfish. Among the shrubs grow highly 

 xerophile grasses and other perennial herbs, among which certain 

 bulb- and tuber-plants, which are in summer totally leafless, are 

 especially prominent. In the spaces between these, numerous 

 annual herbs are found in winter, of which, however, only undefm- 

 able rests remain in the summer time. From this it is evident 

 that the vegetation here is a typical shrub-steppe. 



Closest by the coast the deciduous species of Euphorbia are 

 prominent by their uncommon frequency beside the tall Euphorbias 

 and Kleinias. The evergreen shrubs which grow among them are 

 nearly all small and insignificant or number few individuals. In a 

 height of about 200 m above the level of the sea, where the air is 

 already perceivably more moist, the flora becomes richer in species, 

 and especially the evergreen species become more numerous and 

 frequent. In many places the steppe positively assumes the aspect 

 of a thicket where Aeonium Lindleyi and Rubia fruticosa are met 



