Greinar (Vísindafélag Íslendinga) - 01.01.1967, Síða 66

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are large bare patches, where the gannets have colonized.
The dominant species of the puffin colony vegetation is
Festuca rubra with associated species Stellaria media,
Matricaria maritima and Cochlearia officinalis. The Fes-
tuca is fairly dense on the level ground at the summit,
but sparser on the slopes, where the associated species
are more in evidence. It may be noted that to the south
of the central ridge rainwater collects in a small depres-
sion, on the edges of which Poa annua was growing. In
the outer margins of the puffin colony and towards the
gannet colony Puccinella maritima, Atriplex patula and
Cochlearia officinális were present.
In all 7 species of vascular plants have been found on
Súlnasker (Table II).
Geirfuglasker
Geirfuglasker is sheer on all sides, about 58 m high and
0.02 sq. km in area. The rock is for the most part level
on top, with scattered vegetation which has clearly been
considerably damaged by tephra from the Surtsey erup-
tion. Before this the Puccinella seems to have formed
continuous carpets of vegetation, but it was now smother-
ed by the tephra. There was still some growth on higher
points and at the cliff edge where the tephra had not
been able to lodge. Altogether 4 species of vascular
plants were found: PuccineTla maritima, Atriplex patula,
Cochlearia officinalis and Matricaria maritima. The last
mentioned were in flower.
Thrídrangar
This is a group of skerries to the north-west of the is-
land of Heimaey. The highest of them, Vitadrangur, is
about 40 m and rises sheer from the sea. Here two spe-
cies of vascular plants have been found: Puccinella mari-
tima and Cochlearia officinalis, though less than a hun-
dred individual plants of each species.