The Botany of Iceland - 01.12.1945, Blaðsíða 42

384
STEINDÓR STEINDÓRSSON
the flói is a plant formation in which the soil at any rate during part
of the year is flooded by water, which is, as a rule, stagnant. An ex-
ception in this respect is, however, formed by the “Verlandungs” flói.
The surface is level or with occasional scattered knolls. The vegetation
is continuous except when the flói is in the changing stage, when it may
be intersected by small pools and grooves. Peat formation is, as a rule,
abundant in the lowland flói, whereas it is very inconsiderable in the
alpine flói, where the soil is very sandy. No peat formation is found in
the “Verlandungs” flói. The moss vegetation is rather sparse, especially
in the alpine flói. The formation is poor in species, especially in the
alpine type. The vegetation is characterised by Cyperaceae, and in the
alpine flói often by Calamagrostis. Of the life-forms the geophytes
dominate, but in the highland flói hemicryptophytes and chamaephytes
occur in abundance, while hydrophytes and helophytes attain their
maximum percentage in the flói. Of the species groups erected by
Molholm Hansenitis the E-groups, that is to say, the southern
species, which always dominate in the flói.
No plant formation, perhaps, shows such a small difference between
the biological spectra of the lowland and of the highland as precisely
the flói. The snow- or ice-covering is probably rather prolonged, and
on account of the moisture the bottom of the flói will always be
relatively cold in the summer, but the ice-covering protects it against
the severest cold in winter and thus smooths out the great temperature
fluctuations that are otherwise so much felt by the highland vegetation.
I shall briefly point out which formations in the neighbouring
countries are most closely related to the Icelandic flói formation. In
Greenland the “Græskjær” (grass bog), cf. Warming (1888, pp.
129-130) and Rosenvinge (1896, p. 243), as far as I can see, is
the same formation. The “Fjældkær” (mountain bog) described by
Ostenfeld (1908, p. 115) is likewise very similar to the flói,
especially its lowland type. In addition at any rate some of the as-
sociations mentioned by C a j a n d e r of the “Uberschwemmungs- und
Rimpimoore” and the “Dykárr” mentioned by Melin (1917, p. 20)
must be closely related to the Icelandic flói. The same applies to the
“Eriophorum polyslachyum-rcichc Niedermoor” described by F r i e s
and the “Graskrautmoore” in the Sylene region mentioned by N o r d-
h a g e n.
In those parts of the Icelandic highland that have been invest-
igated by me, the flói formation is rarely contir.nous over large areas,
in contrast to what is often the case in the lowland and in the hills