Spruce (Picea sitchensis) is a large coniferous evergreen tree growing to 50-70
m tall, exceptionally to 90 m tall, and with a trunk diameter of up to 5 m. It
is by far the largest species of spruce, and the third tallest conifer species
in the world (after Coast Redwood and Coast Douglas-fir). It acquires its name
from the community of Sitka, Alaska.
The bark is thin and scaly, flaking off in small circular plates 5-20 cm across. The crown is broad conic in young trees, becoming cylindric in older trees; old trees may have no branches in the lowest 30-40 m. The shoots are very pale buff-brown, almost white, and glabrous (hairless) but with prominent pulvini. The leaves are stiff, sharp and needle-like, 15-25 mm long, flattened in cross-section, dark glaucous blue-green above with two or three thin lines of stomata, and blue-white below with two dense bands of stomata.
The cones are pendulous, slender cylindrical, 5-11 cm long and 2 cm broad when closed, opening to 3 cm broad. They have thin, flexible scales 15-20 mm long; the bracts just above the scales are the longest of any spruce, occasionally just exserted and visible on the closed cones. They are green or reddish, maturing pale brown 5-7 months after pollination. The seeds are black, 3 mm long, with a slender, 7-9 mm long pale brown wing.