Rit (Vísindafélag Íslendinga) - 01.06.1975, Blaðsíða 29

Nordhagen 1943 applies that concept. It must he bome in mind,
however, that no heed is paid to the mosses. Therefore a close exa-
mination of them could alter this classification somewhat, but still
I would not anticipate any major changes on account of the pau-
city of moss in the flói. In mire vegetation as a whole it also seems
to me that the moss vegetation does not change radically from one
sociation to another.
In this survey I have examined the vegetation in both highland
and lowland flói areas, because their differences are so slight that
there is no reason to separate them. There are, to be sure, indi-
vidual sociations, which occur almost exclusively either in high-
land or in lowland areas, as will be specified in each instance.
a) Eriophorum-flói — Eriophorum angustifolii
By far the most numerous of flói sociations are those of the
Eriophorum flói, since E. angustifolium is the most common flói
plant throughout the country, both in the highland and the low-
Nnd, and wherever it occurs it is so abundant that it constitutes the
tnain characteristic of the vegetation cover, as is clearly indicated
by the Icelandic names brokflói, fífuflói or fífusund.
The Eriophorum flói changes in appearance as the summer
wears on. In early smnmer it is dark green in colour, but later
when the seed of Eriophorum ripens the flói turns snow-white.
When fall approaches and the seeds have blown away the flói is
clad in a reddish brown mantle. There is usually a lot of withered
grass in it and even throughout the winter green leaves may be
found among the dead blades of grass. For this reason sheep fre-
qtient the flói in early spring before green grass is to be found else-
where. E. angustifolium is often quite large, especially when in the
proximity of ponds and pools. Its leaves often reach 80-90 cm. in
length and measure 1 cm. in width. Normally, however, it is much
smaller. Most often the vegetation bed of the Eriophorum flói is
continuous and the dense growth and tangles of withered grass
irnpede any significant development of moss. Where the flói is
Wettest there often occur bald patches. E. angustifolium grows all
°ver the flói area, but to varying extent in individual sociations,
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