THE AZORES 



371 



tain. Though doubtless greatly extended by the destruction of 

 the forests since the discovery of the islands, the moors have probably 

 always formed a conspicuous feature of the mountain of Pico around 

 the base of the steep-sided central cone. Without differentiating 

 here between the drier and wetter areas, the most striking features 

 are the bracken (Pteris aquilina), the large tussocks of Polytrichum, 

 and the beds of Sphagnum. Their general characters are often 

 those of a Devonshire moor, as on Dartmoor; and most of the 

 characteristic species exist in both regions. Amongst the most 

 frequent flowering plants are Anagallis tenella, Calluna vulgaris, 

 Erythrcea massoni, Hydrocotyle vulgaris, Luzula purpureo-splendens, 

 Lysimachia nemorum (var. azorica), Menziesia polifolia, Polygala 

 vulgaris, Potentilla tormentilla, Sibthorpia europcea, Thymus serpyllum 

 (var. angustifolius), Viola palustris, and among the sedges, Car ex 

 flava. Lycopodium selago is common, and Blechnum spicant also 

 occurs. Water-holes exist in the more boggy ground, and around 

 the edges and in the water of these pools grow Callitriche aquatica, 

 Carex stellulata, Littorella lacustris, Peplis portula, Potamogeton 

 polygonifolius, Scirpus fluitans, S. multicaulis, etc. 



The Prevailing Climatic Conditions on the Upper Slopes 

 of the Mountain of Pico. — With regard to this point it may be 

 stated that the cloud-belt or rainy zone, 2000 to 5000 feet, corresponds 

 roughly to the Juniper zone and to the belt of the upland moors. 

 The " region of clouds," as Watson terms it, is suggestively described 

 by him as the region of boreal and marsh plants (Loud. Journ. Bot., 

 II., 394). With reference to the higher levels between 6000 feet and 

 the summit (7600 feet), although the nature of the surface of crum- 

 bling lava and cinders would primarily determine the type of plants 

 adapted for growing on steep slopes of this character, the choice 

 would be further restricted to plants capable of withstanding in 

 such an exposed situation the relatively dry atmosphere, the fierce 

 rays of the sun in summer, the frost and snow of winter, and the 

 stormy winds that buffet these heights during much of the year. 



Whilst the rainfall would be much less on the high levels than in 

 the cloud-invested Juniper zone and upland moors below, its de- 

 ficiency would be partly compensated for by the heavy dews. The 

 amount of sunshine must be considerably greater here than in the 

 zones of the woods below. The mere concealment of the peak by 

 clouds, when viewed from the coast, by no means always implies 

 that the summit is cloud-capt. Not infrequently, when the writer 

 had reached the upper limit of the cloud-belt through a driving 

 wet mist, he found the upper third of the mountain exposed under 

 a clear sky to the full glare of the sun and rising out of a billowy 

 sea of clouds of dazzling whiteness, like an island in the midst of 

 Arctic snows. 



Although the daily range of temperature would be greater, it is 

 very probable that the monthly means of the temperature of the air 

 in the shade on the higher slopes of the mountain would approximate 

 those for the elevated region of Dartmoor in the south-west of England, 

 between 1500 and 2000 feet above the sea, a range, let us suppose, of 

 from 33° in January to about 58° Fahr. in July. Snow comes and 



