The Botany of Iceland - 01.12.1945, Síða 157

THE VEGETATION OF CENTRAI, ICELAND
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Occurrence in Sáta
Salix herbacea Common
Polygonum viviþarum Common
Poa alþina Common
Cerastium alþinum Common
Silene acaulis Common
Group II. Species comraon at 850 m but absent or
very rare at greater altitudes.
Agrostis canina
Calamagrostis neglecta Very rare
Equisetum arvense Common up to 700 m
Salix glauca Very rare
Gnaþhalium suþinum
Rumex Acetosa
Taraxacum croceum
Veronica alþina
Group III. Species common below 850 m but rare
at higher altitudes.
Festuca rubra
Carex rigida
Thalictrum alþinum
Equisetum variegatum
Phleum alþinum
Sibbaldia þrocumbens
Common
Comraon up to 700 m
Very rare
Common up to 700 m
Very rare
Group IV. Species common above 850 m, absent
below this altitude.
Festuca ovina Common above 700 m
Saxifraga oþþositifolia Common.
Group V. Species common above 850 m, rare below
this altitude.
Ameria vulgaris Common.
This comparison shows the same as the biological spectra, viz. that
the upper limits for the distribution of the greater number of species
lie much lower in Sáta than in Loðmundur. On the other hand, suf-
ficient observations on the vertical distribution of the individual species
have not been made to allow us to draw further conclusions from them.
This single comparison between the relations of the vegetation to
the altitude and the different exposure shows distinctly that there is