The Sitka
Spruce, picea sitchensis, is an
evergreen tree native to the
Pacific coast from southern
Alaska South through the
Puget Sound area. The tree rarely grows more than eighty km from the
Pacific, or above elevations of 600 m. The reason for this is the Sitka needles need to remain moist to transpire, and the perpetual mist of these
Pacific forests provides this. The tree was first introduced into Botany by
David Douglas, namesake of the
Douglas-fir. Douglas noted the exceptional hardness of the
wood and predicted it would be well suited for cultivation in such places
Britain.
The large-scale physical appearance of the Sitka varies greatly depending on its climate. The costal trees are short and gnarled from the driving Pacific winds. They also are often found with enormous cancerous knots in their twisted braches, which have origins currently unknown to science. One suggested cause is the bite of an insect on a leaf bud could trigger the rapid growth of the knots. Inland Sitkas grow more vertically and commonly reach heights of 70 m.
Identification of the Sitka Spruce is not difficult. With most spruces, the needles are 4 sided and can be rolled between two fingers. However Sitka's are somewhat flattened in comparison. The needles on a branch should be firm and quite sharp, radiating off all sides of the stem. Dead twigs have a characteristic pattern of small holes marking where each needle grew from. Seed cones are red and roughly 7 cm long with thin, semi-irregular scales.
One historical curiosity regarding the Sitka is that is was the wood of choice for the framing of the Spruce Goose airplane built for Howard Hughes.