24 The Irish Naturalist. February, 



Irish Lusitanian species, Saxifraga lunbrosa, so protean in 

 its Kerry hybrids, re-appears in this zone after a long interval 

 at its upper limit of 5,800 feet. Frequent with us at sea- 

 level in Kerry and ]\Iayo, it is quite sub-alpine in the Penin- 

 sula, and in the Serra Dr. Henriques places its lower limit 

 at 2,300 feet. Two Gentians here make their first ap- 

 pearance, the alpine G. liitea which finds its upper limit in 

 this zone, and G. Pneumonanthe w^hich ascends into the 

 Summit Zone VI., where it is one of the most characteristic 

 and abundant species and has been observed by every visitor 

 to the Serra {observado por todos os que teem visitado a Serra). 

 ' In the vSummit or Upper Alpine Zone (VI.), 6,100 to 

 0,500 feet, the flora is reduced to forty-five species, and 

 of these no less than nineteen or 42 per cent, are Irish, 

 eighteen being South Kerry species. The nature of the 

 soil is well shown by the fact that ten of these nineteen 

 species are strongly marked calcifuges, such as Polygala 

 serpyllacea, Viola palustris, Cotyledon Umbilicus , Saxifraga 

 stellaris, Junciis squarrosus and Nardus stricta. In the com- 

 bined floras of the tw^o upper zones, V. and VI., the pro- 

 portion of Irish species is quite as large. It is thirty-nine 

 out of ninety-one, or almost 43 per cent., only one of the 

 thirty-nine, Allosonis crispus, the Parsley Fern, being absent 

 from South Kerry. 



The influence of increase of elevation expressing itself 

 through climatic change is shown not only in the substi- 

 tution of northern for southern plant types, but in the rate 

 of impoverishment in the flora. Taking the upper 1,500 

 feet or so of the Kerry highlands and of the Serra da 

 Estrella, the areas lying above 2,000 feet in Kerry and above 

 5,000 feet in Portugal, we find a remarkably close agreement 

 in the rate of diminution of the floras when compared in 

 each case with the floras of the immediately preceding 

 lower zone. A rise of 1,414 feet in Kerry reduces the flora 

 from 173 to forty-eight species, a loss of 125 or 72*2 per 

 cent. : a similar, or not greatly dissimilar rise (1,570 feet) 

 in the Serra reduces its flora from 166 to forty-five, a loss of 

 121 or 72*9 per cent. In other words, taking impoverish- 

 ment in floral diversity as a criterion of climate, the climate 



