Bigcountry,
The bows I made from ash were only because that was the "traditional" wood of the Odawa. I have made them from grey elm, red elm, Ironwood, hard maple and several others. While the Odawa would use the ash (traditionally) the Ojibwa and Pottawatomii used ironwood (traditionally) You can make scalloped bows from any of the good bow woods.
Most all of the Great Lakes area tribes had one or more sorts of scalloped bows. All of the Iroquois nations, Fox/Saulk, Menominii, Shawnee, and others I cant call to mind this instant....For what it is worth the Iroquois used a lot of hickory and I believe that the Shawnee did as well.
The quarter sawn thing is from when a stave is split down you sometimes wind up with a "sliver" that is too narrow to use as is. If you lay that down on its side you have a "quartersawed" board and yes they do make excellent bows....but the vast majority were probably regular type of staves.
Hope that helps some
rich