The Botany of Iceland - 01.12.1930, Page 50
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H. M0LHOLM HANSEN
The Mosathembur Vegetation. Cf. fig. 4, and table 9 A-B.
On the more prominent parts of Lvngdalsheiði, from which
the snow is at once swept away by the wind in the winter, we
find the mosathembur vegetation developed. Even a long distance
off this type of vegetation is easily recognisable bjr its yellowish
hue. This colour is due to Grimmia hypnoides which covers the
surface in a dense and deep elastic carpet. When the Grimmia heath
is sufficiently large, the moss carpet is, as it were, split up into
large tablets separated by systems of lines; the lines of one system
as a rule converge towards a point in the lower edge of the moss
carpet, another system forming larger or smaller angles with the
first one. Tliese lines do not extend into the surrounding mo, there
we find the usual knoll formation.
Table 9 A gives the circling results of the phanerogamous flora
of the mosathembur vegetation. The five first columns represent
Table 9 A.
The Mosathembur Vegetation on Lýngdalsheiöi.
1—5 Localities in Lvngdalur. c. 200 m above sea levcl, 2/t 1925. 6—10.
Hrólfshólar 280—320 m above sea lcvel, lfi 1925. 11 Tlirasaborgir,
c. 400 m above sea level, 1925. (25. Vto m2)
1 2 3 4 5 6 7 8 . ,0 11
Carex rigida A 3 (i 96 88 84 96 96 48 36 56 44 24 32
Salix herbacea A 3 Ch > 24 4 4 40 100 92 100 100 100 80
Festuca rubra E 4 H 56 28 44 56 56 > > 28 > > >
Thalictrum alpinum ... A 2 H 72 20 36 28 48 > > 24 4 28
Polygonum viviparum.. A 3 G 8 20 12 > 28 32 28 32 36 48 8
Equisetum pratense .... E 2 G 4 16 > 20 8 > > 28 8 4 >
Armeria vulgaris A 3 Ch > 4 4 8 4 4 8 20 16 12 >
Silenc acaulis A 3 Cb > 4 > > 12 4 4 8 16 20 >
Empetrum nigrum E 4 Cb > > » > 8 8 8 8 12 8 >
Juncus trifidus A 2 H > > » > 4 4 8 > 8 4 >
Calium Normanni A 1 H 8 4 > > 12 > > > > > >
Cerastium alpinum .... A 3 Ch 8 4 > > 12 4 4 > >
Fcstuca ovina . E 4 H > > 4 > > 4 , > 4 4 >
Loiseleuria procumbens A 2 Ch > > > > > > > > 4 > *
I.uzula spicata A 2 H > > > > 12 > > > 8 4 >
Vaccinium uliginosum . E 4 Cb 4 > >
Equisetum variegatum . A 3 H 16 > > > > > > > >
Humex acetosa E 3 H > > 4 > > > > , > >
Agrostis canina E 3 H > > > > 4 > > > >