The Botany of Iceland - 01.12.1945, Page 112

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STEINDÓR STEINDÓRSSON
Laki, at c. 700 m altitude, and analysis 6 in Varmafell at c. 600 m;
both localities had a western exposure.
Fig. 9. Grimmia heath (Salix herbacea—Polygonum viviparum-Assoc.).
2. Carex rigida—Salix herbacea—Polygonum viviparum-Ass.
(Tab. XVII. A-B, 5, 7; XVIII. A-B, 1-4, 7-8).
The main difference between this and the preceding association is
that Carex rigida is very abundant here, always setting its mark on the
physiognomy of the association. Otherwise chiefly the same dominants
are found in both associations, but in addition Equisetum variegatum
occurs here. Other frequent species are Equisetum arvense, Salix glauca,
and Euphrasia lalifolia, which were either lacking or of sparse occur-
rence in association 1. The association is richer in species and shows a
greater density of species than the preceding one. It has a higher G
percentage and a lower H percentage than the latter. G and Gh seem
to occur in the same quantities. The association is, as a rule, found in
damper and more exposed places than association 1, and probably also
has a thicker snow-covering.
Analyses XVII, 5-7 were made on Kýlingur, as already stated. A
greater number of gramineous plants are represented in analysis 5 than
is otherwise the case in this association, so here it approaches the brek-
kur formation to some extent. Analysis 6, however, shows the most