The Botany of Iceland - 01.12.1930, Blaðsíða 49

IV. THE ICELANDIC LOWLAND FORMATIONS.
A. LÝNGDALSHEIÐI.
If from some elevated point, say Hrólfshólar or Thrasaborgir, (cfr.
figs. 2 & 3) we try to get a general idea of the vegetation on
Lýngdalsheiði, it will, at that distance, appear to us as an immense
monotonous gréyish green carpet sprinkled with smaller or larger
patches of a yellowish or vivid green colour. These tliree shades
of colour answer to the three most widespread types of vegetation
on Lýngdalsheiði, viz. the mo, which forms the bulk of the vege-
tation, the Grimmia heath, mosathembur, which covers the
more prominent parts of the landscape as a yellowish carpet, and
the snow patches, geiri, which form fresh green oases in the
shelter of slopes and hills or in the old beds of rivulets.
This is how the landscape appears in the vegetation period.
Earlier in the year, e. g. at the close of the period when the snow
nielts, the mo and mosathembur vegetations have their natural co-
lour, while the snow still covers the geiri vegetation. In winter the
nro as well as the geiri vegetation are covered with snow, while
the mosathembur vegetalion is bare.
Of less importance than these three types are a few other vege-
tation types. Wliere there is a strong wind on the sleeper parts, the
vegelation and the layer of mould blow away and leave a soil
covered with stones and gravel which forms the starling point for
the melar vegetation. On llie numerous small cones deposited
hy the liltle streams of melting snow, especially in Lvngdalen, but
also on the ílat parts ot the volcanic shield we find the valllendi
vegetation, and on areas not sufficiently drained there occurs
the mýri vegetation.
In the following we shall subject these 6 types of vegetation
lo a closer analysis.