Rit (Vísindafélag Íslendinga) - 01.06.1975, Page 46

nants, but C. rariflora and Calamagrostis neglecta show a consider-
able frequency. On the whole this sociation is to be found at some
of the wettest parts in the mýri formation, and it is often a transi-
tional form between flói and mýri.
I have observed the sociation at Ásunnarstaðir in Breiðdalur at
an altitude of 350 metres above sea level, where it occurs in con-
siderable quantity and Salix glauca is conspicuous.
12. E. angustifolium — Calamagrostis neglecta sociation
(Tab. IIIv. A-B 1-9)
All studies of this sociation are from the highland areas, since
it almost exclusively occurs there. In my work in 1945 (p. 345)
I assume it to be rare, but later observations of mine have shown
that it is fairly widely distributed throughout the highland, although
extensive tracts are seldom encountered on each location.
Two character species dominate altogether, but it depends on
circmnstances which one has more covering. E. angustifolium do-
minates most often in physiognomy and in the wettest areas it also
has the more covering. Constant accompanying species hardly
exist, but still Salix glauca and Polygonum viviparum occur there
with regularity, although they do not appear in all analyses. C.
rariflora sometimes occurs in considerable abundance e.g. analysis
no. 6, which perhaps should more properly have been classified
with sociation 6, but the distinction between these two sociations
at time becomes vague. On occasion Salix glauca is very conspicu-
ous in this sociation, and I have in my work of 1945 separated it
as a specific sociation, but I have abandoned this view, since it rather
constitutes an intermediate form of sociation 8 or 6. The species
are few. E percentage is relatively high for a highland sociation
and H percentage is higher than normal in flói vegetation.
The sociation always occurs in the driest parts of the flói, often
in the form of a belt around E. angustifolium — C. rariflora so-
ciation, where the soil is so dry that this terrain dries up mostly
for a part of the summer, except in wet smnmers, in which instance
there is little difference between this vegetation type and Calamag-
rostis mire. The soil is often sandy, either because of blown sand
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