MOORLANB ASSOCIATIONS 251 



(usually dwarf), Salix repens, Polygala serpyllacea (heath- 

 milkwort), Pedicularis sylvatica (lousewort), and Luzula 

 campestris are frequently found. Other characteristic 

 plants are : Potentilla Tormentilla, Galium saxatile, Pteris 

 aquilina, Thymus Serpyllum, Achillea Millefolium, Hier- 

 acium Pilosella, Campanula rotundifolia, Veronica offi- 

 cinalis, Euphrasia officinalis, Teucrium Scorodonia, Rumex 

 Acetosdla, and various species of Ruhus. 



Nardus stricta-Association. — On poorer soils, especially 

 in the sub-alpine zone (1,000 to 2,000 feet), Nardus' sir icta 

 (matgrass), which is found sparingly at lower levels, 

 becomes dominant. Festuca ovina, Aira ftexuosa, and 

 Agrostis vulgaris also occur, with Molinia ccerulea in the 

 wetter parts. Calluna is usually less frequent than in the 

 preceding association, but Vaccinium Myrtillus is more 

 abundant. Potentilla Tormentilla, Galium saxatile, Rumex 

 Acetosdla, and Luzula campestris are still very common, 

 and mixed with these are plants characteristic of high 

 altitudes — -e.g., Juncus squarrosus, Lycopodium Sdago, and 

 L. clavatum. 



Molinia-Bog. — Where the drainage is very bad and the 

 soil wet, Nardus stricta is displaced by Molinia ccerulea. 

 Associated with the latter are many bog-plants — e.g., 

 Juncus effusus, J. conglomeratus, Eriophorum vaginatum 

 (cotton-grass), Aira ccespitosa, Narthecium ossifragum, 

 Hydrocotyle vulgaris, Vaccinium Oxycoccus, Erica Tetralix, 

 Rhynchospora alba, Carex (G. Goodenoivii and other 

 species), Sphagnum, etc. Above 2,000 feet the Molinia-bog 

 passes over into cotton-grass moor. 



Summit-Heath. — ^At high altitudes (1,500 to 2,500 feet) 

 a summit-heath, intermediate in character between the 

 alpine-pasture and the Vaccinium-moor, is developed. 

 It consists chiefly of Nardus stricta and Juncus squarrosus, 

 with Vaccinium Myrtillus sometimes sharing dominance. 

 A few plants found at lower levels still persist — e.g., Aira 

 flexuosa, Potentilla Tormentilla, Galium saxatile, Euphrasia 

 officinalis, and Luzula campestris — but alpine plants are 

 frequent— -e.g'., Alchemilla alpina, Lycopodium, Selago, 

 L. clavatum, Empetrum nigrum (crowberry), Vaccinium 

 Vitis-idcea (cowberry), Antennaria dioica, and ia the 

 wetter parts Rubus Chamcemorus, Vaccinium uliginosum 

 (mountain blaeberry), and Eriophorum. 



