708 



GEOGRAPHICAL BOTANY. 



Cerastium alpimun. 



latifolium. 



Veronica sazatilis. 

 alpma. 



Solidago Virgaurea (dwarf form). 



Saussurea alpina. 



Sonchus alpinua. 



Erigeron alpinus. 



Poa alpina. 



Silene acaulis. 



Lychnis alpina. 



Bartsia alpina. 



Jvmcus castaneus. 



Salix reticulata. 



lapponnm. ' 



Sadleri. 



Astragalus alpinus. 

 Oxytropis campestris. 



Cystopteris montana. 

 Juncus biglumis. 



trifidus. 



Gentiana niralis. 

 Cherleria sedoides. 

 Sibbaldia procumbens. 

 Myosotis alpestris. 

 Carex rariflora. 



rupestris. 



Vahlii (alpina). 



vaginata. 



frigida. 



Cerastium trigynum. 

 Silena maritima. 

 Sagina nivalis. 

 Alsine rubella. 

 Saxifraga livularis. 

 Carex lagopina. 



On the summits of some of these mountains the following plants 

 are met with : — 



Luzula spicata. 



Arraeria maritima (alpine form). 



CocUearia officinalis, var. alpina. 



Gnaphalium supinum. 



Carex rigida. 



Draba rupestris. 



Salix herbacea. 



Luzula arcuata. 

 Saxifraga cemua, 

 Andraea (several species). 

 Trichostomum lanuginosum. 

 Gyrophora (several species). 

 Cetraria nivalis. 

 Lecidea (several species). 



Edward Forbes followed Watson in his views of distribution, and 

 promulgated a theory in regard to the origin of the flora of Britain. 

 He considers the vegetation of Great Britain and Ireland as composed 

 of several floras, which are to be reckoned outposts separated by 

 geological changes from more extended areas. The following five 

 floras, according to him, make up the vegetation of Britain and 

 Ireland : — 



1. A -west Pyrenean flora (Iberian or Asturian type), confined to the moun- 

 tainous districts of the west and south-west of Ireland, characterised by botanical 

 peculiarities, which depend on the presence of a few prolific species belonging to 

 the families Saxifragaceae, Ericaceae, Lentibulariacese, and Cruciferse. The nearest 

 parts where these plants are native is the north of Spain. The species are Saxi- 

 fraga umbrosa, S. elegans, S. hirsuta, S. Geum, S. hirta, S. affinis, Erica Mac- 

 kaiana, E. mediterranea, E. cUiaris, Dabeocia polifolia, Arbutus Unedo, Pinguicula 

 grandiflora, Arabis ciliata, Sibthorpia europaea, Euphorbia hyberna, SimethLs 

 bicolor, Trichomanes radicans. 



2. A flora in the south-west of England and south-east of Ireland (Armoricaii 

 type), which is intimately related to that of the Channel Isles and the neighbour- 

 ing coast of France (Brittany and Normandy). This is Watson's Atlantic type. 

 In the Channel Isles we have such peculiar plants as Ranunculus ophioglos- 

 sifolius, Sinapis Cheiranthus, Eruca,strum incanum, Arthrolobium ebracteatum, 

 Linaria pelisseriana, Echium violaceum, Orchis laxiflora, Gymnogramme lep- 

 tophylla, etc. Again, in the south-west of England, we meet with Helianthemum 



