258 



SIXTH REPORT — 1836. 



If, in the first place, we compare the vegetation of Ireland 

 with that of Scotland, we find that climate has exercised a power- 

 ful influence. Ireland is situated more to the south than Scot- 

 land, and its mountains are not so high; it is also more exposed 

 to the Western Ocean, hence its climate is more characterized hy 

 moisture : Scotland is therefore much more rich in Alpine plants 

 than Ireland, as the following list of those found in Scotland 

 and not in Ireland will show. On the other hand the mildness 

 of the Irish climate is perhaps the cause why plants are found 

 on the western coast whose relative habitats are the mountains of 

 Spain and Portugal. It is, however, difficult to account for the 

 loccdities of a few plants as they occur in Ireland. Thus Heli- 

 anthenmm vulgare, so common in Scotland and England, al- 

 though one of the first plants that presents itself to our view 

 on the rocks about Portpatrick, has not yet been found in Ire- 

 land unless in the Island of Arran on the western coast ; and 

 Astragalus hypoglottis, so common about Edinburgh and else- 

 where in Scotland, is in Ireland confined to the same locality. 



It may also not be unworthy of remark, that Arenaria venia, 

 which grows on the basaltic rocks of Arthur's Seat, is found on 

 the same kind of rock at Magillegan, County of Derry. I have, 

 however, specimens of the same plant from the west coast of 

 Clare, where the rocks are, as far as I have observed, composed 

 of limestone. 



List of some of the more remarkable Alpine and other plants 

 of Scotland which are not found in Ireland : 



Veronica alpina 

 „ saxatilis 



Eriophorum capitatum 



Alopecurus alpinus 



Phleum alpinum 

 „ Michelii 



Aira alpina 



Hierochloe boreal is 



Avena planiculmis 



Poa laxa 



Cornus suecica 



Myosotis alpestris 



Primula scotica 

 „ farinosa 



Azalea procumbens 



Gentiana nivalis 



Sibbaldia procumbens 



Meum Athamanticum 



Juncus balticus 



Juncus filiformis 



„ biglumis 



„ triglumis 



„ trifidus 



„ castaneus 



„ tenuis 

 Luzula arcuata 



„ spicata 

 Trientalis europsea 

 Menziesia ccerulea 

 Vaccinium uliginosum 

 Epilobium alpinum 



„ alsinifolium 



Polygonum viviparum 

 Pyrola uniflora 

 Arbutus alpina 

 Saxifraga nivalis 

 „ cernua 

 „ rivularis 



