The Botany of Iceland - 01.12.1945, Blaðsíða 74

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STEINDÓR STEINDORSSON
g. Elyna Bellardi—Campanula rotundifolia-Ass., rich in Gramineae.
(Tab. IX. A-B, 9).
This association agrees entirely with association 1 and should per-
haps be regarded as a variant of it. The analysis was made in Víðidalur
at an altitude of ca. 420 m; it shows the species composition of the
most typical brekkur vegetation in Víðidalur on the lower part of the
mountain sides. The difference in altitude from association 1 gives a
satisfactory explanation of the lower A percentage and the greater
abundance in species here than in that association. The analysis was
taken on a steep slope with a southward exposure and with a particular-
ly luxuriant vegetation. This association is extensively distributed in
Víðidalur and shares the space of the lower mountain sides with herb
snow-patches and Salix scrub. Campanula rotundifolia, which is one
of the dominants, is well known as one of the character species of
East Iceland, but it is only of sporadic occurrence in other parts of the
country. The association is in full accordance with J ó n s s o n’s “Græs-
li” (grassy slopes).
4. Cerastium alpinum—Festuca rubra-Ass. (Tab. IX. A-B, 8).
As this association is represented by one analysis only, I will merely
describe the conditions prevailing in that locality. It is situated on the
south side of the mountain Kýlingur at an altitude of c. 700 m, at the
boundary between the brekkur formation and the Grimmia heath. In
addition to the character species, Polygonum viviparum, Salix herbacea,
5. glauca, and Euphrasia sp. are frequent. In spite of the great altitude,
the association is rich in species, which must be due to the circumstance
that it occurs on a slope which affords particularly good shelter. On
the other hand, the A percentage is fairly high, while the life-form
spectrum is in good agreement with association 1. The association is
only sparsely distributed, though I saw it here and there on the moun-
tain sides of Landmannaafrjettur.
5. Alchemilla alpina—Salix herbacea-Ass. (Tab. IX. A-B, 10).
The only analysis was taken on Síðumannaafrjettur in a steep slope
with a westward exposure. The vegetation is not continuous, and physiog-
nomically and as to species composition it resembles the snow-patch
very much, but the terrain is of such a character that a long-lasting