62 H. MØLHOLM HANSEN 
species in the three formations; if compared with table 11, it will 
further show the agreement between the mo at Björk and that of 
Lyngdalur. 
The Elyna Mo. Table 14 A, 1—4. The dominant here is Elyna 
Bellardi. It occurs especially at the top of the knolls and with 
its brown, tufted stems it contributes markedly to the peculiar 
physiognomy of the vegetation. Other characteristic plants are 
Silene acaulis, Cerastium alpinum, Trisetum spicatum, and Poa glauca. 
These species attain their finest development here even though they 
are also found in the other formations. Further it is characteristic 
of the Elyna mo that a number of species otherwise always present 
in the mo are rare or absent here, viz. Vaccinim uliginosum, Calluna 
vulgaris, Arctostaphylos uva ursi, Deschampsia flexuosa, Galium boreale, 
and Luzula multiflora. All these plants are southern species. 
The Arctostaphylos mo. Table 14 A, 5—7. Physiognomically 
characteristic of this formaiion are above all Arctostaphylos uva ursi, 
Calluna vulgaris, and Vaccinium uliginosum; further there occur Des- 
champsia flexuosa, Galium boreale, Luzu lamultiflora, and Anthoxanthum 
odoratum. On the other hand, Elyna Bellardi, Selaginella selaginoides, 
Silene acaulis, Cerastium alpinum, Trisetum spicatum, and Poa glauca 
are not dominant, a feature by which this formation differs from 
the Elyna mo. The difference between the two mo formations thus 
consists in the fact that the Elyna mo has many arctic but com- 
paratively few southern species in contrast to the Arctostaphylos 
mo in which the southern species are dominant. This difference is 
decidedly due to the difference in the snow-covering. From both for- 
mations the species requiring moisture, which occur in the Empetrum 
mo, are absent. 
The Calluna-Empetrum Mo. As mentioned above, this for- 
mation occurs as a narrow border between the Arctostaphylos mo 
and the jadar, and it is particularly well developed where the ground 
is slightly inclined. The most striking difference between this and 
the above-mentioned formation is the absence of Arctostaphylos 
uva ursi. Owing to the immediate vicinity of the jadar some of 
the plants characteristic of that formation are met with, though 
sporadically, thus Carex sparsiflora, Cardamine pratensis, Deschampsia 
cespilosa, Taraxacum officinale, Agrostis tenuis, Equisetum arvense, 
Viola palustris, Salix lanata, and S. phylicifolia. 
