‘Tis the season for fragrant evergreens. Fresh, woody, crisp, sharp or earthy–evergreen trees and boughs bring olfactory bliss to anyone who dares take a sniff. Each conifer has its own unique smell derived from chemical compounds in their needles and bark. Collectively these chemicals are called terpenes (based on 5-carbon units known as isoprenes) and are usually produced as part of the tree’s defense mechanism–warding off potential pests and disease–among a range of other functions. For humans, however, there is mounting evidence that forest scents may also have many potential therapeutic benefits; making a walk in the forest (a.k.a. forest bathing), just that much more appealing
As for me, the health benefits of terpenes is– like the frost on a cold winter morning– a welcome bonus! Thus, this winter I have set out to not only visually observe the many different species of conifer in my local forests, but smell them–crushing needles all the way. Today, I give you my findings thus far:
Douglas-fir
Douglas-fir can be identified by its soft, flat, 1-1.5 inch needles that spiral around each branch with two white bloom lines on the underside. When pinched or crushed, Douglas-fir needles have a mild sweet lemon and woody scent. Look for their distinct cones pointing downward with three-pronged bracts that stick out from beneath each scale or their dark pointed buds to help confirm identification.
Western redcedar
Tiny, flat-scale like leaves, often with a butterfly shaped bloom on the underside, arrange onto droopy sprays of foliage that fall opposite each other on each branch. This moisture-loving conifer’s leaves are delightfully sugary-sweet smelling with perhaps a hint of pineapple or pear. If you are lucky, you may find some of its rose-bud shaped cones hanging in clusters from the branches.
Western hemlock
Short, flat soft needles of variable length (no longer than ¾ an inch), arrange themselves irregularly around each branch, creating what I like to call the “bedhead” effect. This shade-tolerant conifer’s needles smell faintly like grapefruit when crushed. On a nice day, watch the sunrays scatter through the hemlock canopy; look up and find its drooping leader–a telltale hemlock trait.
Ponderosa pine
Very long, fairly stiff needles (5-10 inches) grow from the ponderosa in bundles of three. When crushed these needles smell woody and sharp, like turpentine (unsurprisingly). Notice the thick puzzle-piece shaped bark of the ponderosa pine–a helpful adaptation to low-intensity fire. If you find a mature tree, take a whiff of the bark, as well, as it is known to give off a sweet vanilla or caramel scent, especially when warmed by the sun.
Grand fir
Two-ranked shiny, dark green needles, with two-white stomatal bands below, splay out like the keys of a grand piano. As for the smell, well this one is a favorite–warm and citrusy, like tangerines. Their stiff branches give the grand fir a stately more structural appearance, similar to other firs, with cones that face upwards high in the branches.
So, go on a walk in your local forest and bask in the many sights and smells it offers. Enjoy the complexity that nature offers as you roam. Stop and smell an evergreen.
