Douglas fir belongs to the genus Pseudotsuga (False hemlock) and is a member of the pine family (Pinaceae).
Douglas fir (Pseudotsuga menziesii) is a conifer species which, in the UK, has reached heights of over 60m and flowers April to May.
Lifespan: in its native range the oldest known Douglas fir is estimated to be 1400 years old.
Characteristics
On the young tree, the bark is grey-green with resin blisters that release a strong fragrance. With age, bark becomes purple-brown with horizontal cracks; when mature it is thick and corky with wide, pale-brown fissures. The bark is non-flammable to protect the tree from fires in its native range. Branches are whorled and ascending. The buds help in identification; they are red-brown, scaly and slender, tapering to a point (up to 7mm); they resemble beech tree buds.
Douglas fir foliage resembles that of silver firs (Abies spp.) Needles are solitary, flat, soft, slightly pointed (1–2.5cm) long; dark green above, below paler with two white bands. The foliage emits a sweet, fruity resinous scent. It hangs in dense, heavy, pendulous masses.
Douglas fir is monoecious: both male and female flowers are found on the same tree. Male flowers are pendulous, oval clusters of yellow stamens growing on the underside of last year’s shoots near the tip. Female flowers are upright tufts or brushes, green to pinkish red, growing at the tips of twigs. The tree is wind pollinated.
Female flowers ripen rapidly into cones which are 5–8cm, oval, slightly elongated and hang downward. Protruding from each scale on the cone is a distinctive three-pointed bract which is unique among conifers. The seeds are oval and fixed to an oval, brown, papery wing.
|