Common names can be confusing--and that is certainly the case with this group of trees. The Pacific Northwest has four species of trees that are called cedars, but none of them are truly cedars. In fact, they don't even resemble true cedars. True cedars belong to the genus Cedrus and bear their evergreen needles in dense clusters on small, woody spur shoots. Their cones are large, sit upright on their branches, and fall apart when the seeds are ripe. True cedars are native only to the Mediterranean and Himalayan regions of the world.
The Pacific Northwest's false cedars have tiny, scale-like foliage and small cones that remain on the tree long after their seeds are gone. Why then are they called "cedars"? Although we can't be sure, it's probably because of their wood. In ancient Rome,Cedrus referred to a group of trees with fragrant wood. Our "cedars" also have aromatic wood, and that's probably how the confusion in names first started.
It's easy to recognize our false cedars as a group, but it's more difficult to tell one from another. Their tiny, scale-like leaves overlap like shingles and form flat sprays like a fern. Some have distinctive patterns of white bloom on their undersides; others don't. To make things even more complex, the four separate species fall into three different genera. Cones are often the best way to tell them apart.
For more information on the incense-cedar native to the Pacific Northwest, go to the species page or see p.15 of "Trees to Know in Oregon".
For more information on the arborvitae native to the Pacific Northwest, go to the species page or see p.16 of "Trees to Know in Oregon".
For more information on the white-cedar native to the Pacific Northwest, go to the species page or see p.18 of "Trees to Know in Oregon".