Rit (Vísindafélag Íslendinga) - 01.06.1975, Blaðsíða 124

ly predominant. The Salix species were conspicuous in physiog-
nomy. This sociation, which might he referred to as a Carex micro-
glochin — Salix glauca sociation occurs widely in the highland
where the conditions are similar.
I have observed another C. microglochin sociation at Krossa-
staðir in Hörgárdalur. It grew on the bank of a stream in a shallow
gully or hollow where it covered a narrow strip along the stream.
C. microglochin and Carex dioica were dominants, hoth in physiog-
nomy and covering and they were similar in abundance. Some
Scirpus pauciflorus occurred and a little Eriophorum angustifolimn.
Other main species were the following: Agrostis canina, Alchemilla
alpina, A. vestita, Carex capillaris, C. capitata, C. Bigelowii, Em-
petrum hermafroditum, Festuca rubra, Juncus alpinus, J. balticus,
J. filiformis, Nardus stricta. There are indications of a rather heavy
snow cover. Similar C. microglochin sociations occur widely, but
always in small patches and often where the topography resembles
that described above.
c. Gramineous mýri — Deschampsiétum cæspitosae
Gramineous vegetation tends to become dominant in the driest
patches of the mire, particularly on the border of damp areas. In
such cases an Equisetum mire is often located between the grami-
neous mire and a C. nigra mire or flói (level mire), but the grami-
neous mire, on the other hand, may phase into grassfield.
The main species of the gramineous mire are the following: Des-
champsia cæspitosa, Agrostis tenuis, A. canina, Festuca rubra, and
Carex nigra. There is considerable fluctuation as to which species
becomes predominant, but generally C. nigra has the greatest cov-
ering, although one or two gramineous plants dominate in physiog-
nomy. The gramineous mire is common all over the country but
it rarely extends over large areas. Sometimes herbaceous plants
become prominent in the gramineous mire. Two observations are
available here of two sociations, both belonging to the gramineous
mire, but nevertheless markedly different. The former, the Des-
champsia cæspitosa sociation, represents the common gramineous
mire, so that the bulk of its description could well be regarded as
applicable to gramineous mires in general.
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