The Botany of Iceland - 01.12.1932, Side 9

FUNGI OF ICELAND
457
vegetation which condition the growth of the fungi. As actual
woods are entirely absent in Iceland, or only present in the shape
of low birch copses in sheltered valleys and on moist valley slopes,
it might be expected, from the occurrence and distribution of the
larger fungi in Central Europe, that but few of these would be
present in Iceland, and that they would chiefly occur in tlie
aforementioned birch copses. This, however, is by no means the
case. For though the number of known species of the larger fungi
in Iceland is not very great (about 150), the individual species have a
wide distribution and are very frequent in some localities, even out-
side the birch copses. In river plains, on mountain slopes, in out-
lying pastures and homefields, occur, primarily, the larger fungi also
to be found outside forests in Central Europe, for instanc.e species
of the genera Mycena, Tricholoma, Omphalia, Russuliopsis, Hygro-
phorus, Leptonia, Psalliota, Stropharia, Panaeolus, Galera, Naucoria,
Inocybe, Lycoperdon, and Bovista. But there also occur species of
genera that chiefly or exclusively inhabit woods, such as Cortinarius,
Pholiota and Russula. Of tliese genera Cortinarius is almost exclu-
sively an inhabitant of woods in Central Europe; but several species
of it are very numerously represented in Iceland in river plains,
fiord valleys, and knolly moorland tracts. It would seein, therefore
that these fungi do not prefer our woods on account of their trees
and hushes, but on account ol' the special climate prevalent there,
a climate whicli may be found in Iceland outside the woods, and
which is especially cliaracterised hy a relatively greater moisture
of tlie atmosphere tlian that usually present outside woods in
Central Europe.
The sporophores of certain of these fungi show peculiar adapta-
tions to the somewhat altered environment. Thus, in river plains and
knolly outlying pastures, among grasses, sedges and mosses, several
species of the genera Inocybe and Cortinarius occur in dense clusters.
They have short stems and small pilei, whereas tlie same species
in Central Europe, as forest fungi, form scattered sporophores with
long stems and larger pilei. The advantage gained in the former
case is tliat the sporophores, on account of their shorter sterns,
develop in a stratum of the atmosphere in which they are not
exposed to desiccation, and the numerous small pilei can develop
just as many spores as the fewer but larger ones.
Further, veiled forms occur, with the veil so well developed,
that until they are closely examined, one is apt to regard them as