Around here Fraxinus species are called white, green, and black. All three have wood that is hard and flexible and will do the job.
Find a piece with grain as parallel to the edges of the board as you can find. You will probably have to rip your own strips. Emerald ash borer may make your search difficult.
White ash will conform to the sheer curvature of most canoes without any need for steaming or other such measures. As was said, straight grain ash is best, if you can find it.
Yes, one whitewater canoe I rerailed was very full and bulbous in the ends so there was a lot of inward curvature to the sheer line.
In order to get the ash to conform a bit better I supported the ends of the gunwales on sawhorses, hung dumbbells from paracord along its length, and periodically poured scalding hot water on the wood.
It took a little while but it worked reasonably well.