The Botany of Iceland - 01.12.1945, Blaðsíða 20

362
STEINDÓR STEINDÓRSSON
Nearest the mountains there are some sandy stretches, the greater part
of which, however, are so damp that no actual blown sand is formed.
This damp sandy area is largely covered by Eriophorum Scheuchzeri
and Equisetum arvense.
4. Jökulgil and Hattve r.—A narrow valley called Jökulgil
extends southeastward from the aforementioned Laugar. The whole
valley bottom is devoid of vegetation, as the glacier stream which runs
through it floods it and prevents any vegetation from gaining a foot-
hold. The mountains on either side are made up of liparite; they are
very steep, and the walls are mostly covered by screes. The vegetation
occurs in very small and scattered patches, containing mainly Salix
herbacea and Saxifraga species. An exception is formed, however, by
a small oasis, H a 11 v e r, found around some hot springs and
resembling Laugar in all essentials.
5. Jökuldalir is the easternmost locality investigated by me
in these parts. Fairly large valleys occur, whose bottoms as regards
vegetation are highly reminiscent of Kýlingar in the damp places, while
the less damp places remind one of the regions around Landmanna-
hellir. In the first places there occur Salix heaths, a form of vegetation
which is only found in the easternmost part of the region, that is to
say, east of Laugar. On the mountain sides there are mainly gravelly
flats covered by a sparse vegetation. Here in Jökuldalir the effects of
the blown sand are much less conspicuous than farther westward. Still
farther eastward, towards the region around Skaftártunga, there are
extensive heaths with good pastures in the summer.
B. Brúaröræfi.
By this name I denote the whole area investigated by me between
the rivers Jökulsá á Fjöllum and Jökulsá á Brú
although part of it actually belongs to Möðrudalsöræfi. The area is
bounded on the south by Vatnajökull, while its northern boundary runs
a little north of Arnardalur. The greater part of this highland region
is a rather level plateau, though with some depressions through which
the rivers flow, and these again are separated by low mountain crests
and ridges. However, some higher mountains rise above the plateau,
thus Fagradalsfjall, Arnardalstindar, Þríhyr-
ningsfjöll, and Kverkhnúkarani. The vegetation is al-