Greinar (Vísindafélag Íslendinga) - 01.01.1942, Blaðsíða 10

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it, it is found in many places but never over more than
narrow strips of ground. Table I, 2 shows the Potentilla
anserina — Poa pratensis —- Ass. Both the distinctive
species characterise the Association and cover about equal
areas. This Association is only found in places lying higher
and drier than the other. The tide can only very seldom
reach it and it is also to be found only in small patches.
The limits of these belts of different growths in places
where both the Ass. are found together are always very
clear.
b. Pond vegetation.
In most of the ponds there is some vegetation besides
Chlorophyceae of which there is always plenty. The most
common Phanerogam in the ponds is Hippuris vulgaris,
especially the variety var. maritima. It forms large beds
in the “Vatnið” and elsewhere. Other species which, how-
ever, grow preferably on the banks at the edges of the
pond-vegetation where it merges into the marsh-vegeta-
tion are Ranunculus hyperboreus and Montia lampros-
perma.
c. Marsh-vegetation (mýri).
All the hollows in Æðey are covered with marsh-vege-
tation. Most of this is characteristic marsh vegetation
(flói), i. e. the surface is level and the soil so wet that the
water stands near the surface and even covers it in rainy
weather, on the other hand the ground will be fairly dry
in a dry season. Among these level areas are spread numer-
ous knolly strips of ground which are usually covere'd
with vegetation of a type different from that of the
surrounding marsh. The analyses which I made in these
groups show the composition with regard to species and
the results are given in Table II. All the analyses were
made by C. Raunkiærs’ circling method.