Douglas Fir (Pseudotsuga menziesii)
Douglas fir has both male and female flowers are found on the same tree. Male flowers are oval clusters of yellow stamens growing on the underside of the previous year's shoots. Female flowers are green to red, upright tufts, and grow at the tips of twigs.
After pollination by wind, female flowers develop into oval cones, which hang straight down from the branches and change in colour from yellow to pink to light brown. From each scale protrudes a unique three-pointed bract.
Douglas fir is an evergreen conifer that can grow to 55m and live for more than 1,000 years. The bark of young trees is grey-green with highly scented blisters, and becomes purple-brown, thick and corky with horizontal fissures over time.
Look out for the trunk which has resin-filled blisters, and the scales on cones which have three pointed tips. When crushed, the leaves have a sweet resin smell.
WHERE TO FIND
Douglas fir is native to North America but was brought to the UK in 1827 by botanist David Douglas and it can now be found in a variety of habitats, including open forests with plenty of moss and rainy conditions. It thrives in western areas of the UK, where rainfall is higher.
VALUE TO WILDLIFE
The Caledonian forest is a priority habitat under the UK Biodiversity Action Plan and is home to rare species such as the creeping lady’s tresses and lesser twayblade orchids; the Scottish wood ant and Rannoch looper; and the capercaillie, crested tit and Scottish crossbill. Mammals include red squirrel, pine marten and Scottish wildcat.
Because the trees are so long-lived, they provide deadwood cavities which birds and bats shelter in. Being tall, they also make perfect nesting sites for larger birds of prey, such as buzzards, sparrowhawks and hobbies.
The spruce carpet and dwarf pug moths feed on the needles, while the seeds are eaten by finches and small mammals. In Scotland, Douglas fir forests provide habitats for the red squirrel and pine marten.