128 THE ESSEX NATURALIST
Monterey Pine (Pinus radiata D. Don) whose home is a very
restricted area of California. It was introduced into Britain in
1833 and has been planted in Devon and Cornwall and elsewhere
where the climate is moist. It does not produce a good timber
but where bulk is required is probably one of the best trees to
plant in Britain, for it may grow at the rate of three feet in a year,
with an annual increase in diameter of as much as two and a half
inches. This pine has been widely planted in Australasia and
South Africa where its growth is phenomenal.
Corsican Pine (Pinus nigra Arnold v. calabrica (Loud.)
Schneid.) is one of the exotic pines which has come to stay in this
country. A tree of southern Europe, it has become a favourite
with foresters for large-scale planting because of its high yield of
timber arid the fact that it can be grown successfully on poor types
of forest soils. Large areas in East Anglia have been planted with
this tree by the Forestry Commission. Corsican Pine timber is
very similar to that of the Scots Pine (red deal) although some-
what inferior in quality, but the generally larger bulk yield of the
Corsican Pine is an advantage and mining timber can be grown
in from 25-35 years. The Corsican Pine was introduced into
Britain nearly a couple of hundred years ago, although it is only
in recent years that its economic possibilities have been realised.
The closely related Austrian Pine (Pinus nigra Arnold), which is
one of' the commonest pines of parks and gardens in Britain,
was not introduced until 1835. Useful as a shelter-belt tree,
the very habit which makes it of value in this respect—the
retention of its lower branches—is detrimental to its use as a
timber tree, for it results in very knotty wood which, in addition,
is rather coarse and for all intents of no economic value.
Common or Norway Spruce (Picea Abies (L.) Karst.) was,
apparently, a native of Britain before the Ice Age, but it did not
re-establish itself in postglacial times and was introduced some
time in the Middle Ages (probably before 1500). Although so
common a tree of our countryside at the present time, it is not
really naturalised and rarely tends to establish itself naturally.
It is a valuable tree to the forester, for it will thrive on poor wet
soils and in exposed situations, although of course it grows better
in a more kindly environment. Its wood, the white deal of
commerce, is rather less valuable than that of Scots Pine, except
for special purposes, but the young trees are in demand as Christ-
mas trees. It is not a tree which grows rapidly in its youth and a
Christmas tree two to three feet high is at least seven years old.
The Silver Fir (Abies alba Mill.) is another European conifer
which was introduced into Britain from central and southern
Europe early in the 17th century. It has the distinction of being
one of the largest European trees and even in Britain may attain