looks like yellowwood but leaves are opposite

vjane

I have a volunteer tree about 4 feet high which was growing next to the house. It's very pretty but we have no room for another yard tree, so I dug it up and put it in a patio tub, where it seems to be doing well. Its leaves are a lovely dark green. From various online tree identification sites, I thought I had identified it as a yellowwood, Cladrastis kentuckea (lutea). The leaves are broadleaf & compound. However, although the leaflets otherwise look exactly like those in pictures of yellowwood I looked at, they are opposite, not alternating. I'm in Oregon, and I'm not sure the yellowwood grows this far west. Any thoughts on identification?

Eden Keeper

Trees with opposite compound leaves are among the easiest to key out in North America. There are only 3 genera in my area with pinnate leaves that are also in Oregon and these are ash, elderberry, and maple specifically box-elder. Of these I would suspect it is Oregon ash, Fraxinus latifolia Benth., since the other two have toothed leaves unlike yellowwood. Yellowwood is local in parts of the east so as you suspect that is not likely to be it due to the leaf arrangement, besides definitive keys for yellowood are alternate leaflets and buds hidden by the swollen base of the petiole. I've also grown yellowwood from seed and it takes years for one to reach 4 feet thus they bring a premium price, but it would be worth it if you could grow one since it is described as the most beautiful North American tree when it blooms (2-5 year intervals in the wild) and in my case 17+ years from seed since they haven't bloomed yet.

vjane

Based on Eden Keeper's excellent reply, I think it must be an Oregon ash. Here are some photos - do they confirm the identification?

Thanks!!

Brent Ferris

When I google Oregon Ash, its leaves are more lanceolate.

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