The Botany of Iceland - 01.12.1930, Síða 104

94
H. M0LHOLM HANSEN
acaulis, Armeria (here and there), Cerastium alpinum, Tofieldia bore-
alis, Juncus trifidus, Luzula spicata and L. multiflora, Alchemilla al-
pina, Pingvicula vulgaris, Carex rigida, Festuca rubra, and further,
where the soil is a littte damp, Saxifraga Hirculus, and Sedum
villosum”.
On the high plateau to the south of Vatnsdalur the heather
mo is “stunted and patchy” and “the gravellj' subsoil comes to the
surface everywhere.” The composition of the species is as follows:
Empetrum, Betula nana, Salix glauca, (here and there), Salix her-
bacea, a very scattered growth of Vaccinium uliginosum, Drgas octo-
petala, (rather sparingly), Elyna Bellardi, Silene acaulis, Armeria mari-
tima, Cerastium alpinum, Polygonum viviparum, Trisetum spicatum,
Poa caesia, Festuca ovina v. vivipara, Thalictrum alpinum, and Arabis
petrœa.
The melar vegetation on Vatnsdalshals is described as
follows; “Silene acaulis and in some places Dryas are the most
conspicuous plants, notably in the flowering season but, in addition
to these and several other plants growing among the heather, there
also occur Silene maritima, Saxifraga opposiiifolia, S. decipiens,
S. nivalis, and on high, almost quite bare, gravelly flats Arenaria
ciliata, Alsine verna, f. propinqua, Arabis petrœa f. glabra and hispida,
Draba verna, Trisetum subspicatum, fíumex acetosella, Armeria mari-
tima and others.”
In the highlands south of the valley the melar vegetation “re-
sembles that of Valnsdalshals, but is much poorer in species.”
On Vatnsdalsfjall, “on the gravelly crest of the mountain,
c. 2000' above the sea, the typical mountain íield or melar vegetation,
where the plants occur in isolated specimens with large bare patches
between, attains its full development, almost wdthout the invasion
of any foreign elements. I observed the following species: fíanun-
culus glacialis, Luzula arcuata, (both characteristic of high moun-
tains), Luzula spicata, Poa pratensis, P. alpina (vivipar), P. caesia,
Aira alpina, Saxífraga nivalis, S. oppositifolia, S. hypnoides, Cerastium
alpinum, Erigeron alpinus, Pohggonum viviparum, Silene acaulis,
Dryas octopetala (in small quantity), Potentilla maculata, Ranunculus
acer, Armeria sibirica, Salix herbacea, Trisetum subspicalum."
On Víðidalsfjall, at a height of c. 3000' the melar vegetation had
the following composition: Silene acaulis, Saxifraga oppositifolia,
Sedum acre, fíanunculus glacialis, further Cerastium alpinum f. lanata,
Poa alpina, Aira alpina, Poa caesia, Saxifraga hypnoides, S. decipiens,