IV. THE ICELANDIC LOWLAND FORMATIONS. 
A. LYNGDALSHEIDI. 
F from some elevated point, say Hrölfshölar or Thrasaborgir, (cfr. 
figs. 2 & 3) we try to get a general idea of the vegetation on 
Lyngdalsheidi, it will, at that distance, appear to us as an immense 
monotonous greyish green carpet sprinkled with smaller or larger 
patches of a yellowish or vivid green colour. These three shades 
of colour answer to the three most widespread types of vegetation 
on Lyngdalsheidi, 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 
melts, the mo and mosathembur vegetations have their natural co- 
lour, while the snow still covers the geiri vegetation. In winter the 
mo as well as the geiri vegetation are covered with snow, while 
the mosathembur vegetation is bare. 
Of less importance than these three types are a few other vege- 
tation types. Where there is a strong wind on the steeper parts, the 
vegetation and the layer of mould blow away and leave a soil 
covered with stones and gravel which forms the starting point for 
the melar vegetation. On the numerous small cones deposited 
by the little streams of melting snow, especially in Lyngdalen, but 
also on the flat parts ot the volcanic shield we find the valllendi 
vegetation, and on areas not sufficiently drained there occurs 
the myri vegetation. 
In the following we shall subject these 6 types of vegetation 
to a closer analysis. 
