PLANT-LIFE
In relation to its northerly position, Norway has a very luxuriant
vegetation; of phanerogams alone, there are about 1500 species
growing wild in the country.
The largeness of this number is partly due to the unusual
mildness of the climate in proportion to the high latitude; but it
is also partly caused by the great extent of the country, which affords
space for essential differences between its various * parts. In the
northern districts and on the mountains, for instance, there is an
arctic vegetation, in the south-east a continental Central-European
flora, and along the west coast there is a number of species
which require an insular climate, and are indigenous to Western
Europe.
The richest vegetation in the country is found in the southeast,
around the Kristiania Fjord and the large lakes, Mjosen,
Eandsfjord and Tyrifjord; in the neigbourhood of Kristiania alone,
there are no less than 900 wild phanerogams. The climate there
is continental, with warm, not very short summers ; the bird-cherry
(Prunus Padus) blossoms round Kristiania on the 17th May, fruit-
trees about the 20th. In Vestre Slidre in Yaldres, at about 61°
N. Lat. and 9° E. Long., where the bottom of the valley is almost
1300 feet above the sea, thé bird-cherry blossoms on the 30th
May, the first night-frosts appear about the 12th September, and
the leaves fall about the 26th of the same month.
The character of the vegetation in the whole of south-eastern
Norway is . determined by the conifers, which form thick forests
from sea-level up to a height of from 2500 to 3000 feet. Scotch
fir (Pinus silvestris) and spruce (Picea excelsa) grow side by side, the
pine, however, predominating on dry ground, and going somewhat
higher up the mountains than the spruce can grow. Among the
conifers there is always a sprinkling of birches (Betula odorata),
rowan-tree (Sorbus aueuparia) ; and aspen (Populus tremula).
In the lowest parts, up to1 about 1600 feet above the sea,
there is also a number of Central-European deciduous trees here
and there among the conifers. On talus slopes and warm hills,
a luxuriant growth of oak (Quercus pedunculata), ash (Fraxinus
excelsior), lime (Tilia parvifolia), maple (Acer platanoides), elm
(TJlmus montana), and. lowland birch (Betula verrucosa) may be
met with. These trees are secondary to the conifers, and only
occasionally form small woods ; but they nevertheless give to the
lowland flora its characteristic stamp. A number of herbaceous
plants are found together • with them, which also belong to the
continental parts of Central Europe, and which, in Norway, are
only found in the lowlands of the south-east. As examples we
may name thé blue hepatica or liver leaf (Anemone hepatiea),
which' carpets the woods in April and May with its flowers,
as . well [as other perennial spring flowers such as Primula
officinalis, Viola mirabilis, Saxifraga granulata,’ Orobus vernus, • Gle-
choma hederaceum. Here too are several of our rarest orchids,
which are only found on warm dry hills in the south-east, such
as Ophrys my odes, Cephalanthera. rubra, Neottia nidus avis.
The late Norwegian phytogeographer, Axeu ' B u ttt, has
called this zone of vegetation the region of «boreal» (half-
hardy) deciduous trçes. I t is characterised not only by the deciduous
trees and continental^southern, herbaceous plants, but also
by the fact that the cultivation of com is mainly confined to this
region. Certain kinds of corn, e. g. barley, can indeed ripen as
high as 2600 feet above the. sea, but as the harvest is more
or less uncertain, there is not much corn cultivation done above
Î600 feet.
Above the region of boreal deciduous trees, there is a zone
in' which the conifers are almost alone in the field. I t extends
to about 2600 feet above the sea, though the limit is not everywhere
equally high. I t is highest in the most continental parts of
the country, in 0sterdalen and Gfudbrandsdalen. Here the conifers
so greatly predominate, that they pretty well dislodge all plants
that cannot grow in their shade. In the spruce-woods themselves,
the flora is very deficient in species,' but on the other hand, the