Which one is native to the Pacific Northwest?

One of these plants is native to the PNW. It’s reasonably common and may be growing in a park, open space, or wetland near you. Which one, and what is it?


In the first picture (upper left) is squash — not native to the PNW.

In the second picture (upper right) are hot peppers — not native to the PNW.

In the third picture (lower right) is okra, upside down — not native to the PNW.

In the last picture (lower left) is Oregon ash — a tree native to western Washington, western Oregon, and northern California (but not British Columbia).

The scientific name of Oregon ash is Fraxinus latifolia. “Fraxinus” is an ancient word for ash; the word originally meant spear. “Latifolia” means wide-leaved.

Oregon ash loves soggy ground. It most often grows along streams or ponds or in dips that are submerged in the winter.

Look around in a park or open space near you. If the foliage is visible, look for compound leaves. Oregon ash is one of the only trees of the PNW that has compound leaves. Each compound leaf on an Oregon ash has 5, 7, or 9 leaflets, usually 7, like this:

An Oregon ash tree often has several trunks (called “multi-stemmed”).

The bark on a young Oregon ash is pale gray and smooth, very much like a young red alder, Alnus rubra, or a young cascara, Rhamnus purshiana, both of which may be intermingled with ash. On an older Oregon ash, the bark is darker gray with furrows:

All types of ashes produce a profusion of winged seeds (also called “samara”). The seed itself is encased in one end of the wing. In late summer, ash seeds float gently down or whirl like maple seeds. This enables seeds to travel farther from the mother.

Because Oregon ash often lives in or near ponds, the fallen seeds provide valuable food for frogs and tadpoles.

Oregon ash is one of the relatively few native tree species that requires a female tree and male tree to reproduce (called “dioecious”).

In contrast, for most other tree species of this region, the female reproductive parts and male reproductive parts grow on the same tree. Examples include Douglas-fir (seed cones and pollen cones on the same tree) and bigleaf maple (pistils and stamens in the same flower).

Ash from eastern North America is the only wood commonly used for shovel handles. It also used to be the only wood commonly used for baseball bats, though now many major-league players are switching to maple wood.

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Photo credits

Squash: https://pistonclasico.com/wall/easy-guide-to-growing-luffa-plant, Posted by Serena on July 23, 2019

Hot pepper: https://www.grow-it-organically.com/hot-pepper-varieties.html, ‘Nu Mex Joe Parker’

Okra: https://www.sustainablemarketfarming.com/, Photo by Bridget Aleshire

[All other photos by the author]