The Botany of Iceland - 01.12.1949, Side 14

12
EMIL HADAC
sula bogs are: Heleocharetum palustris, Eriophoretum Scheuchzeri,
Eriophoretum angustifolii, Cariceto-Comaretum, Menyantho-Drepano-
cladetum revolventis; the driest of them, the Empetreto-Caricetum
fuscae, represents a transition to the heath communities (cf. Hadac
1939)-
Amphibious communities of the lakes and pools (Koenigieto-Agro-
stidetum albae, Agrostideto-Ranunculetum reptantis, Subularieto-Ra-
nunculetum reptantis, Ranunculeto-Isoetetum lacustris) are particularly
interesting. On the sea shore a Puccinellietum maritimae boreoatlanti-
cum may be found.
The sand dunes are occupied by Elymetum arenarii and Festucetum
cryophilae. The nitrophile vegetation of the sea shore is represented by
Atriplicetum glabriusculae.
Snow patches are very common on the plateaus; there well known
communities of Anthelietum, Salicetum herbaceae and Sibbaldietum may
be seen. Characteristic for the snow patch communities are e. g. Gna-
phalium supinum, Veronica alpina, Sibbaldia procumbens, Phleum com-
mutatum, Dicranum falcatum etc.
In the neighbourhood of snow patches a very rich community of
Empetreto-Vdccinietum occurs, where Vaccinium uliginosum and V.
Myrtillus, Empetrum hermaphroditum, Alchemilla alpina, A. minor,
Rhacomitrium canescens, are dominating.
A special type of vegetation is represented by the temporarily hydro-
phile community, Nardetum islandicum (Nardus, Viola palustris, Poly-
gonum viviparum, Drepanocladus uncinnatus, Agrostis tenuis etc.)
The spring vegetation is represented mainly by the Philonotidetum
fontanae, with characteristic species as Montia lamprosperma, Epilobium
alsinifolium, Juncus triglumis, Saxifraga stellaris, Mniobryum albicans
etc. The most thermophile community of the area investigated is
probably the Geranieto-Succisetum pratensis on southern slopes of the
Central Highland of Reykjanes, with Geranium silvaticum, Succisa,
Fragaria vesca, Hieracium islandicum, Angelica silvestris, Filipendula
Ulmaria, Orchis maculatus etc.
The complete description of the above plant communities will be
published in a special paper.