The Botany of Iceland - 01.12.1932, Page 8

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POUL LARSEN
S. W. country, but also a sraaller area in the east country.
The finds of C. H. Ostenfeld are mainly derived from the north,
north-west and west country, and Chr. Gronlund has visited both
the east, north and west country. — My own investigations in the
summer of 1922 began in the first part of June in S. W. Iceland, viz.
in the country round Reykjavík, Hafnarfiörður and Þingvellir. In
the latter part of June I continued with the part round Borgar-
Qörður, especially the birch copses near Borg and Norðtúnga. But
my main area of investigation was N. E. Iceland, the region between
the Ofiord Valley and the east coast of Iceland, viz. the 0fiord Valley
itself and the F'njóskadalur running parallel to it, the depression
near Mývatn with Laxádalur, Jökulsá á Heiði from Grímstaðir to
Möðrudalur, Jökulsá á Brú, Lagarfljót with Iceland’s largest birch
copse, and finally the region round Seyðisfjörður.
As will appear from this survey, the south country is the least
explored part of Iceland as regards fungi. The extensive bare sands
along the southern coast of the country cannot, however, be expected
to add to the number of species, for even though there is some
dune vegetation here, a similar vegetation occurs on the extensive
range of dunes along Jökulsá á Heiði. The few samples of the vege-
tation of sands and dunes derived from Helgi Jónsson’s collec-
tion show in the main the same fungi as those occurring on the
plants collected by me on dunes in the interior round Grímstaðir
near Jökulsá á Heiði. And the homefields of the farms in the south
country bear mainly the same vegetation as the homefields in the
rest of the country, and must therefore be supposed to harbour much
the same fungi. On the whole, such large areas of Iceland have now
been investigated that all the different forms of vegetation are repre-
sented, and an addition to the number of species is more likely to
be made through a more thorough examination of details than by
enlarging the area of investigation.
The Special Conditions of Environment offered to
Fungi in Iceland.
Though the fungus flora is greatly dependent on the rest of the
vegetation, we cannol infer from this that the more luxuriant the
vegetation of a country is, the richer and more abundant its fungus
flora will be. At any rate, this does not appljr to the larger fungi.
There must, therefore, be other factors besides the chlorophyllaceous