The Botany of Iceland - 01.12.1945, Síða 19

THE VEGETATION OF CENTRAL ICELAND
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river, H e 11 i s á. The altitude of the valley bottom above the sea is
c. 600 m. The other oases on Landmannaafrjettur lie at the same
altitude. The soil is mostly dry and sandy, though some few boggy
areas occur. Large stretches of the valley bottom are constantly invaded
by sand-drifts. A large lake is found there, also, but as far as I could
see, it was entirely devoid of vegetation. The valley is surrounded by
fairly high mountains made up of tuff. The highest of these is
Loðmundur (1008 m). The mountain sides are covered with
grass to a great extent; thus the south-facing side of Loðmundur is
clothed with grass almost to its uppermost edge except the steepest
parts, where screes or talus slopes are found. Grimmia heaths occur in
several places on the mountain plateaus, while on the mountain sides,
where the snow lingers long, extensive growths of Anthelia are found.
Near this oasis there occurs another, much smaller one, D ó m a-
d a 1 u r; here I only investigated the bottom of the small valley, which
is covered with a continuous grassy carpet in which Calamagrostis
neglecta was predominant. Its vegetation does not differ essentially
from that found near Hellisá. Farther eastward there occur obsidian
lava fields, largely covered with sand and almost devoid of vegetation,
apart from some scattered tufts of Elymus.
2. Laugar and Laugahrau n.—Laugar is a quite small
oasis situated at the margin of a lava field, Laugahraun, and a small
glacier stream, Jökulgilskvísl. This oasis is of a type quite
different from that of the usual highland oases, as it may compare in
luxuriance with the cultivated home-fields of the lowland. This luxuri-
ance is due to a number of hot springs issuing everywhere from the
substratum of the lava. The driest part of the oasis is a grass field
dominated by Trifolium repens, while its wettest portion is a Carex
Goodenoughii bog. The Laugahraun (obsidian lava) situated south of
the oasis supports a very poor moss and phanerogam vegetation.
3. Kýlingaris the name of a tract of land situated right
up by T u n g n a á. In the middle of this oasis rises a small mountain,
Litli Kýlingur, while on the east the depression is bounded by
the mountains Stóri Kýlingur and Kirkjufell. Both the
Kýlingurs are largely covered with vegetation, whereas Kirkjufell must
be said to be entirely devoid of vegetation. A fairly large lake or lagoon
is found at the bottom of the valley; its surroundings consist of a very
moist Eriophorum flói, which is constantly inundated by Tungnaá.
The Botany of Icland. Vol. III. Part IV.
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