Rit (Vísindafélag Íslendinga) - 01.06.1975, Side 95

parum are conspicuous. Carex Bigelowii occurs to a considerable
extent. There are many indications that this is a transitional fomx
to Salix heath. The sociation grows in a rather large area along
a river bank, but there is some seepage of spring water from the
hillsides above which flows through the mire without becoming
stagnant. The Ch percentage it high, but the HH percentage is
lower than in the preceding sociation which is in many respects
related to this one.
54. C. rariflora — Eriopliorum angustifolium, Salix glauea soc.
I have described this sociation before in my paper (Steindórsson
1945 p. 198). No analysis exists. Apart from the character species,
the following occur: Carex Bigelowii, Empetrum hermafroditum,
Vaccinium uliginosum, Saxifraga Hirculus and Pedicularis flam-
mea.
The moss species Sphagnum teres and Hypnum uncinatum are
conspicuous, and Sphagnum characterises the mýri (sloping mire),
the phanerogamous vegetation being sparse everywhere. I have not
studied this sociation elsewhere, except at Fagridalur in Brúaröræfi.
a. 3. Carex Bigeiowii mýri — Caricétum Bigelowii
Corresponding to C. nigra which is a character species in most
lowland mýri tracts, C. Bigelowii is a character species in the
highland mýri areas. It is not possible to define the boundaries
between these two mýri-sociations with absolute certainty, since
these often vary from one part of the country to another according
to location. It may be asserted, however, that the C. nigra mýri
mostly disappears when the elevation reaches 300 m above sea
level, and it is extremely rare above 400 m where it has been re-
placed by the C. Bigelowii mýri. The C. Bigelowii mýri, however,
often occurs at much lower altitudes, for example at Melrakka-
slétta where it almost reaches the sea level. But as far as vegeta-
tion is concerned Melrakkaslétta is in many ways similar to the
less elevated highland at altitudes of 3-400 m. In the West fiords
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