The Botany of Iceland - 01.12.1945, Blaðsíða 48

390
STEINDÓR STEINDÓRSSON
9. Cctrex Lyngbyei—Calamagrostis neglecta-Ass.
(Tab. III. A-B, 3-4).
Actually only analysis 3 is from a typical C. Lyngbyei association.
The other analysis shows rather a transitional form to a flói association
rich in C. rariflora and Salix glauca. Analysis 3 was taken in Fagrida-
lur, where the association is found in some few places under similar
conditions as the preceding association, but only where there is greater
moisture. It is of limited distribution here, and was not noticed in
other places in the highland. Analysis 4 is from Eyjabakkar, from a
small flói-flat situated at the foot of a steep slope, whence water is
constantly oozing, so that the ground is very damp. The snow-covering
here is no doubt much thicker than is otherwise the case in the flói.
Carex Lyngbyei, which is the dominating species here, is generally very
rare in the highland regions investigated by me.
10. Carex rariflora—C. rostratd—C. chordorrhiza-Ass.
(Tab. III. A-B, 5).
The analysis was taken on Síðumannaafrjettur; it shows, also, an
association with a much higher number and density of species than is
otherwise the case in the alpine flói; in that respect it much resembles
the lowland associations, as does the vegetation of Síðumanaafrjettur
altogether. The association, which I did not encounter in other parts
of the highland, forms a narrow belt in very moist soil along lakelets.
It is noteworthy that Carex chordorrhiza dominates here, for it has not
been found elsewhere in the highland, whereas it is very common in
the lowland flói.
b. The M ý r i Vegetation.
Within the mýri series I regard as mýri all the associations which
grow on such dry soil that the ground-water never rises above the sur-
face, or, if it happens, at any rate only for a very short time. The sur-
face of the mýri is always more or less knolly, and the knolls consist
largely of moss. The mýri is always richer in moss than the flói, and
Sphagnum is often very abundant. Otherwise mainly the same genera
of mosses occur in both formations. As a rule the surface of the mýri
is sloping, so the water is not stagnant in the soil. The mýri vegetation
is richer in species than that of the flói, and it always forms a continuous